A method, system, equipment and medium for testing the airtightness of a stratospheric airship capsule.

Abstract

This invention discloses a method, system, equipment, and medium for testing the airtightness of a stratospheric airship capsule. The system includes a capsule inflation device, a capsule volume measurement device, an environmental parameter measurement subsystem, a capsule parameter measurement subsystem, and a data transmission and storage subsystem. The method establishes the relationship between the volume of the capsule under test and the internal and external pressure difference. It measures the internal temperature of the capsule, the internal and external pressure difference, the ambient temperature, and the ambient pressure under different initial pressure difference conditions to obtain the equivalent pore size value for gas leakage under different pressure differences. Based on the flight test design conditions of the stratospheric airship, the gas leakage amount is calculated daily for each day and night during the stationary phase, and the capsule volume, capsule pressure difference, and equivalent pore size value are updated for each day and night until the capsule pressure difference is less than a preset minimum pressure difference value, thus reaching the theoretical stationary time, thereby obtaining the airtightness test results of the stratospheric airship capsule. This invention can improve the accuracy of evaluating the airtightness performance of stratospheric airship capsules.

Description

Technical Field

[0001] This invention relates to the field of airtightness testing technology for flexible inflatable structures, and in particular to a method, system, equipment, and medium for testing the airtightness of a stratospheric airship capsule. Background Technology

[0002] Based on the current methods and equipment used for testing the airtightness of stratospheric airship capsules, the existing testing systems and methods have the following limitations:

[0003] Existing testing equipment primarily employs single or limited sensors to measure the internal temperature, internal-external pressure difference, and ambient temperature and pressure of the airship capsule. The data recording intervals are relatively long, around 30 minutes. However, stratospheric airship capsules are large, and the internal temperature and internal-external pressure difference are not uniformly distributed along the capsule's axial and longitudinal axes. The ambient temperature and pressure are also spatially unevenly distributed, and these measurements change rapidly over time. The current sensor count and data acquisition frequency fail to adequately account for the spatial and temporal non-uniformity of the capsule and environmental parameters, resulting in insufficient test data for accurate measurement and evaluation of the airtightness of the stratospheric airship capsule structure. Existing testing methods assume a constant capsule volume when performing pressure-holding tests on small-sized capsules, neglecting the impact of volume changes on airtightness. Since stratospheric airship capsules are large, flexible, inflatable structures, their volume varies significantly under different internal-external pressure differences, significantly affecting the measurement and evaluation of their airtightness. Existing testing methods primarily employ simple conversion formulas to calculate the airtightness of small-sized capsules. These methods have limited requirements for the testing environment and fail to adequately consider the impact of fluctuations in ambient temperature and pressure, making it difficult to accurately measure and evaluate the airtightness of stratospheric airship capsule structures. Furthermore, existing methods mainly calculate the gas leakage during a one-day hovering period based on helium permeability measurements of the capsule material and the surface area of ​​the stratospheric airship capsule. These methods fail to consider the variations in parameters such as internal temperature, internal and external pressure differences, and capsule volume under actual hovering conditions, and their impact on gas leakage. Consequently, the calculation results are insufficient to accurately predict the buoyancy retention capacity of stratospheric airships during hovering. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method, system, equipment, and medium for testing the airtightness of stratospheric airship capsules, which can improve the accuracy of airtightness testing of stratospheric airship capsules.

[0005] In a first aspect, embodiments of the present invention provide a method for testing the airtightness of a stratospheric airship capsule, the method comprising:

[0006] Acquire actual test data and initial stationary design parameters for the stratospheric airship capsule; wherein, the actual test data includes actual capsule volume, actual internal capsule temperature, actual internal and external pressure difference, actual ambient temperature, and actual ambient pressure; the initial stationary design parameters include ambient pressure, ambient temperature, internal and external pressure difference, average superheat value, capsule volume, and internal gas mass under initial stationary conditions, wherein the average superheat value includes daytime average superheat value and nighttime average superheat value, and the internal and external pressure difference includes daytime internal and external pressure difference and nighttime internal and external pressure difference;

[0007] Based on the curve of the actual bladder volume changing with the pressure difference inside and outside the actual bladder, the actual bladder internal temperature, the actual bladder internal and external pressure, the actual ambient temperature, and the actual ambient pressure, the equivalent pore size of the bladder under different initial pressure difference conditions is calculated based on the principle of mass conservation and the ideal gas equation, and the curve of the equivalent pore size changing with the pressure difference of the bladder is obtained by fitting.

[0008] Based on the actual environmental pressure, the actual internal temperature of the bladder, the actual pressure difference between the inside and outside of the bladder, and the curve of the equivalent pore size changing with the pressure difference of the bladder, the relationship between the gas leakage mass flow rate and the equivalent pore size is constructed.

[0009] Based on the ambient pressure, ambient temperature, daytime average superheat value, and daytime pressure difference between the inside and outside of the capsule under the initial evacuation conditions, the daytime gas leakage is calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Based on the daytime gas leakage and the initial gas mass inside the capsule, the remaining gas mass inside the capsule during the daytime is calculated.

[0010] Based on the ambient pressure, ambient temperature, nighttime average superheat value, and nighttime pressure difference between the inside and outside of the capsule under the initial suffocation conditions, the nighttime gas leakage is calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Based on the nighttime gas leakage and the daytime residual gas mass inside the capsule, the nighttime residual gas mass inside the capsule is calculated.

[0011] Based on the mass of the remaining gas inside the capsule at night, the capsule volume, the pressure difference between the inside and outside of the capsule, and the equivalent pore size are updated using the ideal gas law, the curve of the actual capsule volume changing with the actual pressure difference between the inside and outside of the capsule, and the curve of the equivalent pore size changing with the actual pressure difference between the inside and outside of the capsule.

[0012] Based on the updated capsule volume, pressure difference between inside and outside the capsule, and equivalent pore size, the mass of residual gas inside the capsule at night on the following day is calculated until the updated pressure difference between inside and outside the capsule is less than the preset minimum pressure difference, at which point the theoretical dwell time is reached.

[0013] Based on the theoretical dwell time, the airtightness test results of the stratospheric airship capsule were obtained.

[0014] Compared with the prior art, the first aspect of the present invention has the following beneficial effects:

[0015] This method, based on the principle of mass conservation and the ideal gas law, obtains the equivalent pore size of the bladder under different pressure differential conditions by considering the actual bladder volume, internal temperature, pressure difference, ambient temperature, and ambient pressure. By comprehensively considering these factors, the accuracy of the calculated equivalent pore size is improved. Furthermore, based on the actual ambient pressure, internal temperature, pressure difference, and measured equivalent pore size versus pressure differential curves, a gas leakage mass flow rate is constructed. The relationship between gas leakage mass flow rate and equivalent orifice diameter is established. Based on the environmental pressure, ambient temperature, daytime average superheat, and daytime pressure difference inside and outside the bladder under initial vacuum conditions, the daytime gas leakage rate is calculated using the relationship between gas leakage mass flow rate and equivalent orifice diameter. Based on the daytime gas leakage rate and the initial gas mass inside the bladder, the remaining gas mass inside the bladder during the daytime is calculated. Similarly, based on the environmental pressure, ambient temperature, nighttime average superheat, and nighttime pressure difference inside and outside the bladder under initial vacuum conditions, the nighttime gas leakage rate is calculated using the relationship between gas leakage mass flow rate and equivalent orifice diameter. Based on the nighttime gas leakage rate and the initial gas mass inside the bladder during the daytime... The residual gas mass was calculated to obtain the mass of residual gas inside the capsule at night. By considering the capsule's superheat and the internal and external pressure difference, the relationship between the gas leakage mass flow rate and the equivalent orifice diameter was constructed. This yielded the gas leakage rate and the residual gas mass under different capsule superheat and internal and external pressure differences, covering all ranges of capsule superheat and internal and external pressure differences during stationary operation, thus improving the comprehensiveness and accuracy of capsule airtightness testing. Based on the residual gas mass inside the capsule at night, the ideal gas law, the curve of actual capsule volume versus actual internal and external pressure difference, and the curve of equivalent orifice diameter versus actual internal and external pressure difference were used to update the data. The volume of the capsule, the pressure difference between the inside and outside of the capsule, and the equivalent pore size are updated. Based on these updated values, the mass of the remaining gas inside the capsule at night is calculated for the following day. The theoretical stationary time is reached when the updated pressure difference between the inside and outside of the capsule is less than the preset minimum pressure difference. Based on this theoretical stationary time, the airtightness test results of the stratospheric airship capsule are obtained. By obtaining the theoretical stationary time based on the volume of the capsule, the pressure difference between the inside and outside of the capsule, and the equivalent pore size, the accuracy of the prediction of stationary buoyancy retention capability can be improved, thereby improving the accuracy of the airtightness test of the stratospheric airship capsule.

[0016] According to some embodiments of the present invention, the principle of mass conservation and the ideal gas law are constructed in the following manner:

[0017]

[0018] in, This represents the environmental pressure at the initial time t0 within a given time period. Represents the end time t within a time period. n Environmental pressures, This represents the pressure difference between the inside and outside of the cyst at the initial time t0 within a time period. Represents the end time t within a time period. n The pressure difference between the inside and outside of the cyst, This represents the internal temperature of the cyst at the initial time t0 within a given time period. Represents the end time t within a time period. n The internal ambient temperature, This represents the volume of the vesicle at the initial time t0 within a given time period. Represents the end time t within a time period. n The volume of the cyst, μ represents the flow coefficient, and d m0 Let P(t) represent the equivalent pore size corresponding to the pressure difference between the inside and outside of the bladder at an initial time t0 within a time period, ΔP(t) represent the current ambient pressure, ΔP(t) represent the current pressure difference, T(t) represent the current ambient temperature, and R represent the current ambient temperature. gas This represents the gas constant.

[0019] According to some embodiments of the present invention, the relationship between gas leakage mass flow rate and equivalent orifice diameter is established in the following manner:

[0020]

[0021] Among them, Q d (t) represents the mass flow rate of the gas leak at the current moment, and d m (ΔP(t)) represents the equivalent orifice diameter corresponding to the current pressure difference, and μ represents the flow coefficient.

[0022] According to some embodiments of the present invention, the daytime gas leakage is calculated in the following manner:

[0023]

[0024] Among them, P atm T represents the environmental pressure under initial stalemate conditions. atm ΔT represents the ambient temperature under initial vacancies conditions. day ΔP represents the average diurnal superheat value during the daytime period of stationary airspace. day d represents the intra-day pressure difference between the inside and outside of the cyst during a single day of stationary airspace. day (Δp day ) represents the intra-day pressure difference ΔP within and outside the cyst during a single day of stationary airspace.day The corresponding daytime equivalent aperture, t day R represents the daytime duration during the stationary period, μ represents the flow coefficient, and R represents the daytime duration of a day. gas This represents the gas constant.

[0025] According to some embodiments of the present invention, the amount of gas leakage at night is calculated in the following manner:

[0026]

[0027] Among them, P atm T represents the environmental pressure under initial stalemate conditions. atm ΔT represents the ambient temperature under initial vacancies conditions. night ΔP represents the nighttime average superheat value during a day of stationary stay. night d represents the intraocular and extraocular pressure difference during a day of stationary flight. night (Δp night ) represents the pressure difference ΔP between the inside and outside of the bladder during the nighttime period of a single day. day The corresponding equivalent aperture at night, t night R represents the nighttime of a day during the stationary period, μ represents the flow coefficient, and R represents the flow rate. gas This represents the gas constant.

[0028] Secondly, embodiments of the present invention also provide a stratospheric airship capsule airtightness testing system, the stratospheric airship capsule airtightness testing system comprising:

[0029] A capsule inflation device, which is connected to the stratospheric airship capsule and is used to inflate the stratospheric airship capsule.

[0030] A capsule volume measuring device is used to measure the actual capsule volume of the stratospheric airship under different pressure difference conditions.

[0031] An environmental parameter measurement subsystem is installed around the stratospheric airship capsule to measure the actual ambient temperature and actual ambient pressure around the stratospheric airship capsule.

[0032] A capsule parameter measurement subsystem is installed on the surface and inside the capsule of the stratospheric airship to measure the actual internal temperature and the actual pressure difference between the inside and outside of the capsule.

[0033] The data transmission and storage subsystem is communicatively connected to the environmental parameter measurement subsystem and the capsule parameter measurement subsystem. It is used to transmit the measurement data of the environmental parameter measurement subsystem and the capsule parameter measurement subsystem to the workstation for storage in real time, and to process and analyze the measurement data. The equivalent pore size and theoretical dwell time under different pressure difference conditions are calculated using the stratospheric airship capsule airtightness test method described above.

[0034] Compared with the prior art, the second aspect of the present invention has the following beneficial effects:

[0035] This system measures the volume of a stratospheric airship capsule under different pressure differential conditions using a capsule volume measurement device, considering the impact of volume changes on capsule airtightness and obtaining the variation law of capsule volume with internal and external pressure difference, providing a reliable basis for evaluating capsule airtightness performance. An environmental parameter measurement subsystem measures the ambient temperature and pressure around the stratospheric airship capsule, while a capsule parameter measurement subsystem measures the internal temperature and internal and external pressure difference of the stratospheric airship capsule. By measuring the internal temperature, internal and external pressure difference, ambient temperature, and ambient pressure, the system fully considers the spatial and temporal non-uniformity of capsule and environmental parameter distribution, improving the overall accuracy of capsule and environmental parameter measurements and providing more accurate test data support for capsule airtightness testing. A data transmission and storage subsystem transmits the measurement data from the environmental parameter measurement subsystem and the capsule parameter measurement subsystem to the workstation for storage in real time. The system also processes and analyzes the measurement data to obtain the theoretical dwell time, improving the prediction accuracy of the theoretical dwell time and thus enhancing the accuracy of stratospheric airship capsule airtightness testing. This system uses a full-size stratospheric airship capsule structure as the test object, and comprehensively considers gas permeation of the capsule material under the action of internal and external pressure difference, gas leakage at the connection parts of the capsule structure, and gas leakage caused by damage to the capsule during processing and transportation. It can fully reflect the true state of the stratospheric airship capsule and improve the accuracy of the measurement and evaluation of the airtightness of the stratospheric airship capsule structure.

[0036] According to some embodiments of the present invention, the capsule volume measurement device includes a three-dimensional laser scanner, a stitching target sphere, a tripod, a processing terminal, and processing software; wherein, the three-dimensional laser scanner is used to collect data points of the stratospheric airship capsule and generate point cloud data; the stitching target sphere serves as a standard common target sphere and is used for multi-station scanning and stitching data; the tripod is used to mount the scanner; the processing terminal is a mobile workstation used to process the point cloud data collected by the three-dimensional laser scanner; and the processing software is installed in the processing terminal and used to process the point cloud data.

[0037] According to some embodiments of the present invention, the stratospheric airship capsule airtightness testing system uses distributed wireless sensors to measure the actual internal temperature of the capsule, the actual internal and external pressure difference of the capsule, the actual ambient temperature, and the actual ambient pressure.

[0038] Thirdly, embodiments of the present invention also provide a stratospheric airship capsule airtightness testing device, including at least one control processor and a memory for communicatively connecting to the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor to enable the at least one control processor to perform a stratospheric airship capsule airtightness testing method as described above.

[0039] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to execute a stratospheric airship capsule airtightness testing method as described above.

[0040] It is understood that the beneficial effects of the third and fourth aspects mentioned above compared with the related technologies are the same as the beneficial effects of the first aspect mentioned above compared with the related technologies. Please refer to the relevant description in the first aspect mentioned above, which will not be repeated here. Attached Figure Description

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0042] Figure 1 This is a flowchart of a method for testing the airtightness of a stratospheric airship capsule according to an embodiment of the present invention;

[0043] Figure 2 This is a structural diagram of a stratospheric airship airtightness testing system according to an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of a stratospheric airship airtightness testing system according to another embodiment of the present invention;

[0045] Figure 4 This is a top view of the measurement node arrangement according to an embodiment of the present invention;

[0046] Figure 5 This is a side view of the measurement node arrangement according to an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the capsule airtightness test process according to another embodiment of the present invention;

[0048] Figure 7This is a schematic diagram of the finite element simulation model of the capsule and the volume change curve with pressure difference according to an embodiment of the present invention;

[0049] Figure 8 This is a schematic diagram of the test differential pressure design according to an embodiment of the present invention;

[0050] Figure 9 This is a schematic diagram illustrating the temperature variation with day and night time under the stationary conditions of a stratospheric airship according to an embodiment of the present invention;

[0051] Figure 10 This is a flowchart of the prediction process for the buoyancy retention capability in an embodiment of the present invention. Detailed Implementation

[0052] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0053] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0054] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0055] In the description of this invention, it should be noted that, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0056] Based on the current methods and equipment used for testing the airtightness of stratospheric airship capsules, the existing testing systems and methods have the following limitations:

[0057] Existing testing equipment primarily employs single or limited sensors to measure the internal temperature, internal-external pressure difference, and ambient temperature and pressure of the airship capsule. The data recording intervals are relatively long, around 30 minutes. However, stratospheric airship capsules are large, and the internal temperature and internal-external pressure difference are not uniformly distributed along the capsule's axial and longitudinal axes. The ambient temperature and pressure are also spatially unevenly distributed, and these measurements change rapidly over time. The current sensor count and data acquisition frequency fail to adequately account for the spatial and temporal non-uniformity of the capsule and environmental parameters, resulting in insufficient test data for accurate measurement and evaluation of the airtightness of the stratospheric airship capsule structure. Existing testing methods assume a constant capsule volume when performing pressure-holding tests on small-sized capsules, neglecting the impact of volume changes on airtightness. Since stratospheric airship capsules are large, flexible, inflatable structures, their volume varies significantly under different internal-external pressure differences, significantly affecting the measurement and evaluation of their airtightness. Existing testing methods primarily employ simple conversion formulas to calculate the airtightness of small-sized capsules. These methods have limited requirements for the testing environment and fail to adequately consider the impact of fluctuations in ambient temperature and pressure, making it difficult to accurately measure and evaluate the airtightness of stratospheric airship capsule structures. Furthermore, existing methods mainly calculate the gas leakage during a one-day hovering period based on helium permeability measurements of the capsule material and the surface area of ​​the stratospheric airship capsule. These methods fail to consider the variations in parameters such as internal temperature, internal and external pressure differences, and capsule volume under actual hovering conditions, and their impact on gas leakage. Consequently, the calculation results are insufficient to accurately predict the buoyancy retention capacity of stratospheric airships during hovering.

[0058] To address the aforementioned problems, this invention, based on the principle of mass conservation and the ideal gas law, obtains the equivalent pore size of the capsule under different pressure differential conditions by considering the actual capsule volume, internal temperature, pressure difference, ambient temperature, and ambient pressure. By comprehensively considering these factors, the accuracy of the calculated equivalent pore size is improved. Furthermore, based on the actual ambient pressure, internal temperature, pressure difference, and measured equivalent pore size versus pressure differential curves, a gas... The relationship between gas leakage mass flow rate and equivalent orifice diameter is investigated. Based on the ambient pressure, ambient temperature, daytime average superheat, and daytime pressure difference inside and outside the bladder under initial vacuum conditions, the daytime gas leakage rate is calculated using the relationship between gas leakage mass flow rate and equivalent orifice diameter. Based on the daytime gas leakage rate and the initial gas mass inside the bladder, the remaining gas mass inside the bladder during the daytime is calculated. Based on the ambient pressure, ambient temperature, nighttime average superheat, and nighttime pressure difference inside and outside the bladder under initial vacuum conditions, the nighttime gas leakage rate is calculated using the relationship between gas leakage mass flow rate and equivalent orifice diameter. Based on the nighttime gas leakage rate and the daytime... The mass of residual gas inside the capsule was calculated at night. By considering the capsule's superheat and the pressure difference between the inside and outside, a relationship between the gas leakage mass flow rate and the equivalent orifice diameter was constructed. This yielded the gas leakage rate and the mass of residual gas inside the capsule under different superheat and pressure differences, covering all ranges of superheat and pressure difference during stationary operation, thus improving the comprehensiveness and accuracy of the capsule's airtightness test. Based on the mass of residual gas inside the capsule at night, the ideal gas law, curves showing the actual capsule volume versus the actual pressure difference inside and outside the capsule, and curves showing the equivalent orifice diameter versus the actual pressure difference inside and outside the capsule were used. The system updates the capsule volume, pressure difference between the inside and outside of the capsule, and equivalent pore size. Based on these updated values, the remaining gas mass inside the capsule at night for the following day is calculated. This process continues until the updated pressure difference between the inside and outside of the capsule is less than a preset minimum pressure difference, at which point the theoretical stationary time is reached. Based on this theoretical stationary time, the airtightness test results of the stratospheric airship capsule are obtained. By obtaining the theoretical stationary time based on the capsule volume, pressure difference between the inside and outside of the capsule, and equivalent pore size, the accuracy of predicting stationary buoyancy retention capability can be improved, thereby enhancing the accuracy of the stratospheric airship capsule airtightness test.

[0059] Reference Figure 1 This invention provides a method for testing the airtightness of a stratospheric airship capsule. This method includes, but is not limited to, steps S100 to S800, wherein:

[0060] Step S100: Obtain actual test data and initial stationary design parameters for the stratospheric airship capsule; wherein, the actual test data includes the actual capsule volume, actual internal temperature, actual pressure difference between the inside and outside of the capsule, actual ambient temperature, and actual ambient pressure; the initial stationary design parameters include the ambient pressure, ambient temperature, pressure difference between the inside and outside of the capsule, average superheat value, capsule volume, and internal gas mass under initial stationary conditions, the average superheat value includes the average superheat value during the day and the average superheat value at night, and the pressure difference between the inside and outside of the capsule includes the pressure difference between the inside and outside of the capsule during the day and the pressure difference between the inside and outside of the capsule at night;

[0061] Step S200: Based on the actual capsule volume, actual capsule internal temperature, actual capsule internal and external pressure difference, actual ambient temperature and actual ambient pressure, and based on the principle of mass conservation and the ideal gas law, obtain the equivalent pore size of the capsule under different pressure difference conditions.

[0062] Step S300: Based on the actual environmental pressure, actual internal temperature of the bladder, actual pressure difference between the inside and outside of the bladder, and the measured curve of the equivalent pore size changing with the pressure difference of the bladder, construct the relationship between the gas leakage mass flow rate and the equivalent pore size.

[0063] Step S400: Based on the environmental pressure, ambient temperature, daytime average superheat value, and daytime pressure difference between the inside and outside of the bladder under the initial evacuation conditions, calculate the daytime gas leakage amount using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter, and calculate the daytime residual gas mass inside the bladder based on the daytime gas leakage amount and the initial gas mass inside the bladder.

[0064] Step S500: Based on the ambient pressure, ambient temperature, nighttime average superheat value and nighttime pressure difference inside and outside the bladder under the initial suffocation conditions, calculate the nighttime gas leakage amount using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter, and calculate the nighttime residual gas mass inside the bladder based on the nighttime gas leakage amount and the daytime residual gas mass inside the bladder.

[0065] Step S600: Based on the mass of the remaining gas inside the capsule at night, update the capsule volume, the pressure difference inside and outside the capsule, and the equivalent pore size using the ideal gas law, the curve of the actual capsule volume changing with the actual pressure difference inside and outside the capsule, and the curve of the equivalent pore size changing with the actual pressure difference inside and outside the capsule.

[0066] Step S700: Calculate the mass of the remaining gas inside the capsule at night on the following day based on the updated capsule volume value, the pressure difference between the inside and outside of the capsule, and the equivalent pore size value. The theoretical dwell time is reached when the updated pressure difference between the inside and outside of the capsule is less than the preset minimum pressure difference value.

[0067] Step S800: Obtain the airtightness test results of the stratospheric airship capsule based on the theoretical stationary time.

[0068] In steps S100 to S800 of some embodiments, to make the calculation results more accurate and thus improve the accuracy of the subsequent theoretical stationary time calculation, this embodiment obtains the equivalent pore size of the bladder under different pressure difference conditions based on the principle of mass conservation and the ideal gas law, according to the actual bladder volume, actual internal bladder temperature, actual internal and external pressure difference, actual ambient temperature, and actual ambient pressure. To improve the comprehensiveness and accuracy of the bladder airtightness test, this embodiment constructs the relationship between gas leakage mass flow rate and equivalent pore size based on the actual ambient pressure, actual internal bladder temperature, actual internal and external pressure difference, and the measured equivalent pore size variation curve with bladder pressure difference. Based on the ambient pressure, ambient temperature, daytime average superheat value, and daytime internal and external pressure difference under the initial stationary conditions, the relationship between gas leakage mass flow rate and equivalent pore size is used to calculate the daytime gas leakage. Based on the daytime gas leakage and the initial internal gas mass, the remaining gas mass inside the bladder during the daytime is calculated. Under the conditions of ambient pressure, ambient temperature, nighttime average superheat, and nighttime pressure difference between the inside and outside of the capsule, the nighttime gas leakage is calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Based on the nighttime gas leakage and the daytime residual gas mass inside the capsule, the nighttime residual gas mass inside the capsule is calculated. To improve the accuracy of the theoretical stationary time prediction and thus the accuracy of the stratospheric airship capsule airtightness test, this embodiment updates the capsule volume, pressure difference, and equivalent orifice diameter values ​​based on the nighttime residual gas mass using the ideal gas equation of state, the curve of actual capsule volume versus actual pressure difference between the inside and outside of the capsule, and the curve of equivalent orifice diameter versus actual pressure difference between the inside and outside of the capsule. Based on the updated capsule volume, pressure difference, and equivalent orifice diameter values, the nighttime residual gas mass inside the capsule for the following day is calculated. This process continues until the updated pressure difference between the inside and outside of the capsule is less than a preset minimum pressure difference value, at which point the theoretical stationary time is reached. Based on the theoretical stationary time, the stratospheric airship capsule airtightness test results are obtained.

[0069] In some embodiments, the principle of mass conservation and the ideal gas law are constructed in the following manner:

[0070]

[0071] in, This represents the environmental pressure at the initial time t0 within a given time period. Represents the end time t within a time period. n Environmental pressures, This represents the pressure difference between the inside and outside of the cyst at the initial time t0 within a time period. Represents the end time t within a time period. n The pressure difference between the inside and outside of the cyst, This represents the internal temperature of the cyst at the initial time t0 within a given time period. Represents the end time t within a time period. n The internal ambient temperature, This represents the volume of the vesicle at the initial time t0 within a given time period. Represents the end time t within a time period. n The volume of the cyst, μ represents the flow coefficient, and d m0 Let P(t) represent the equivalent pore size corresponding to the pressure difference between the inside and outside of the bladder at an initial time t0 within a time period, ΔP(t) represent the current ambient pressure, ΔP(t) represent the current pressure difference, T(t) represent the current ambient temperature, and R represent the current ambient temperature. gas This represents the gas constant.

[0072] In this embodiment, the equivalent pore size of the capsule under different pressure difference conditions is obtained based on the principle of mass conservation and the ideal gas law, making the calculation results more accurate and thus improving the accuracy of the subsequent theoretical stationary time calculation.

[0073] In some embodiments, the relationship between gas leakage mass flow rate and equivalent orifice size is established as follows:

[0074]

[0075] Among them, Q d (t) represents the mass flow rate of the gas leak at the current moment, and d m (ΔP(t)) represents the equivalent orifice diameter corresponding to the current pressure difference, and μ represents the flow coefficient.

[0076] In some embodiments, daytime gas leakage is calculated as follows:

[0077]

[0078] Among them, P atm T represents the environmental pressure under initial stalemate conditions. atm ΔT represents the ambient temperature under initial vacancies conditions. day ΔP represents the average diurnal superheat value during the daytime period of stationary airspace. day d represents the intra-day pressure difference between the inside and outside of the cyst during a single day of stationary airspace. day (Δp day ) represents the intra-day pressure difference ΔP within and outside the cyst during a single day of stationary airspace. day The corresponding daytime equivalent aperture, t day R represents the daytime duration during the stationary period, μ represents the flow coefficient, and R represents the daytime duration of a day. gas This represents the gas constant.

[0079] In some embodiments, nighttime gas leakage is calculated as follows:

[0080]

[0081] Among them, P atm T represents the environmental pressure under initial stalemate conditions. atm ΔT represents the ambient temperature under initial vacancies conditions. night ΔP represents the nighttime average superheat value during a day of stationary stay. night d represents the intraocular and extraocular pressure difference during a day of stationary flight. night (Δp night ) represents the pressure difference ΔP between the inside and outside of the bladder during the nighttime period of a single day. day The corresponding equivalent aperture at night, t night R represents the nighttime of a day during the stationary period, μ represents the flow coefficient, and R represents the flow rate. gas This represents the gas constant.

[0082] In this embodiment, the relationship between gas leakage mass flow rate and equivalent orifice diameter is constructed by considering the superheat value of the capsule and the internal and external pressure difference, thereby obtaining the gas leakage amount and internal residual gas mass under different capsule superheat and internal and external pressure differences. This covers all ranges of capsule superheat and internal and external pressure differences during stationary operation, improving the comprehensiveness and accuracy of capsule airtightness testing.

[0083] Reference Figure 2 This invention also provides a stratospheric airship airbag airtightness testing system. This system includes an airbag inflation device 100, an airbag volume measurement device 200, an environmental parameter measurement subsystem 300, an airbag parameter measurement subsystem 400, and a data transmission and storage subsystem 500, wherein:

[0084] A capsule inflation device 100 is connected to the stratospheric airship capsule and is used to inflate the stratospheric airship capsule.

[0085] The capsule volume measuring device 200 is used to measure the actual capsule volume of a stratospheric airship under different pressure differential conditions.

[0086] The environmental parameter measurement subsystem 300 is located around the stratospheric airship capsule and is used to measure the actual ambient temperature and actual ambient pressure around the stratospheric airship capsule.

[0087] The capsule parameter measurement subsystem 400 is set on the surface and inside the capsule of the stratospheric airship and is used to measure the actual internal temperature and the actual pressure difference between the inside and outside of the capsule of the stratospheric airship.

[0088] The data transmission and storage subsystem 500 communicates with the environmental parameter measurement subsystem and the capsule parameter measurement subsystem. It is used to transmit the measurement data of the environmental parameter measurement subsystem and the capsule parameter measurement subsystem to the workstation for storage in real time, and to process and analyze the measurement data. The equivalent orifice value and theoretical dwell time under different pressure difference conditions are calculated using the above-mentioned stratospheric airship capsule airtightness test method.

[0089] In this embodiment, the actual volume of the stratospheric airship capsule under different pressure difference conditions is measured using a capsule volume measuring device. The influence of capsule volume changes on capsule airtightness is considered, and the variation law of the actual capsule volume with the actual internal and external pressure difference is obtained, providing a reliable basis for evaluating the capsule's airtightness performance. The actual ambient temperature and pressure around the stratospheric airship capsule are measured using an environmental parameter measurement subsystem, and the actual internal temperature and actual internal and external pressure difference of the stratospheric airship capsule are measured using a capsule parameter measurement subsystem. By measuring the actual internal temperature, actual internal and external pressure difference of the capsule, ... The system measures actual ambient temperature and pressure to provide more accurate test data for the airtightness testing of the stratospheric airship capsule. The data transmission and storage subsystem transmits measurement data from the environmental parameter measurement subsystem and the capsule parameter measurement subsystem to the workstation for storage in real time. The data is then processed and analyzed to obtain the theoretical dwell time for the stratospheric airship capsule airtightness test. This method improves the accuracy of theoretical dwell time prediction, thereby enhancing the accuracy of the stratospheric airship capsule airtightness test. This system uses a full-size stratospheric airship capsule structure as the test object, comprehensively considering gas permeation under internal and external pressure differences, gas leakage at capsule structure connections, and gas leakage caused by damage during processing and transportation. This comprehensive approach reflects the true state of the stratospheric airship capsule, improving the accuracy of the airtightness measurement and evaluation of the stratospheric airship capsule structure.

[0090] In some embodiments, the capsule volume measurement device includes a 3D laser scanner, a stitching target sphere, a tripod, a processing terminal, and processing software; wherein, the 3D laser scanner is used to collect data points of the stratospheric airship capsule and generate point cloud data; the stitching target sphere serves as a standard common target sphere and is used to scan and stitch data from multiple stations; the tripod is used to mount the scanner; the processing terminal is a mobile workstation used to process the point cloud data collected by the 3D laser scanner; and the processing software is installed in the processing terminal to process the point cloud data.

[0091] In this embodiment, a full-size stratospheric airship capsule structure is used as the test object. This can comprehensively consider gas permeation of the capsule material under the action of internal and external pressure difference, gas leakage at the connection parts of the capsule structure, and gas leakage caused by damage to the capsule during processing and transportation. This can fully reflect the true state of the stratospheric airship capsule, thereby improving the accuracy of the airtightness measurement of the stratospheric airship capsule structure.

[0092] In some embodiments, the stratospheric airship capsule airtightness testing system uses distributed wireless sensors to measure the actual internal temperature of the capsule, the actual pressure difference between the inside and outside of the capsule, the actual ambient temperature, and the actual ambient pressure.

[0093] In this embodiment, a distributed wireless sensor network is used to measure the actual internal temperature of the capsule, the actual pressure difference between the inside and outside of the capsule, as well as the actual ambient temperature and pressure. This fully considers the non-uniformity of the spatial and temporal distribution of capsule and environmental parameters, improves the overall accuracy of capsule and environmental parameter measurements, provides more accurate test data support for capsule airtightness measurement, reduces the difficulty of test system setup, reduces the error rate of on-site setup, and improves airtightness testing efficiency.

[0094] To facilitate understanding by those skilled in the art, a set of preferred embodiments is provided below:

[0095] The technical solution of this embodiment can quickly and efficiently build an airtightness testing environment based on a wireless sensor network, and measure in real time the actual internal temperature and pressure difference parameters of the actual capsule, as well as the actual ambient temperature and pressure parameters. By establishing the relationship between the actual capsule volume and the actual internal and external pressure difference, and calculating the equivalent pore size of the capsule under different pressure difference conditions, and considering the influence of fluctuations in actual ambient temperature and pressure, the gas leakage of the large-size capsule structure of the stratospheric airship can be measured more accurately. Considering the diurnal variation of the actual internal temperature and actual internal and external pressure difference of the capsule under actual flight and hovering conditions, the hovering buoyancy retention capacity can be predicted, and the gas leakage and theoretical hovering time for each day and night during hovering can be obtained. This provides a reference for the airtightness measurement and flight performance prediction of the stratospheric airship capsule. The specific technical solution is as follows:

[0096] (1) Stratospheric airship airbag airtightness testing system.

[0097] The stratospheric airship capsule airtightness testing system includes a capsule inflation device, a capsule volume measurement device, an environmental parameter measurement subsystem, a capsule parameter measurement subsystem, and a data transmission and storage subsystem. It provides a wireless sensor network-based testing environment for full-scale stratospheric airship capsule airtightness testing. The structure of the stratospheric airship capsule airtightness testing system is as follows: Figure 3As shown. In the stratospheric airship capsule airtightness testing system, the capsule inflation device is connected to the capsule under test via inflation tubing; the capsule parameter measurement subsystem is arranged on the surface and inside of the capsule under test; the environmental parameter measurement subsystem is arranged around the capsule under test; the capsule parameter measurement subsystem and the environmental parameter measurement subsystem transmit test data to the data transmission and monitoring subsystem via a wireless transmission protocol; the capsule volume measurement device has a separate processing terminal, which has no physical or communication interface with other parts of the testing system. Before the airtightness test begins, the actual capsule volume is measured to obtain the relationship between the volume of the capsule under test and the actual pressure difference inside and outside the capsule. Specifically:

[0098] 1) Inflation device for the capsule

[0099] The capsule inflation device provides a stable air source for the stratospheric airship capsule airtightness testing system. It is used to inflate the stratospheric airship capsule and includes a high-flow-rate fan, a high-pressure fan, inflation piping, and a control module. The high-flow-rate fan is used for the initial stage of inflation to rapidly inflate the large-sized capsule of the stratospheric airship. The high-pressure fan is used to inflate the capsule to the designed pressure differential value after initial formation. The inflation piping connects the capsule's inflation port to the fan. The control module controls the rate of increase in pressure differential inside and outside the capsule after initial formation, preventing excessively rapid increases that could affect capsule safety. The design specifications of the capsule inflation device are as follows:

[0100] High-flow fans: air volume ≥ 3000m³ 3 / h;

[0101] High-pressure blower: air volume ≥ 20m³ 3 / h, total pressure ≥2000Pa;

[0102] Control module: The rate of increase of internal and external pressure difference is ≤10Pa / min.

[0103] 2) Capsule volume measuring device

[0104] The capsule volume measurement device is used to measure the actual capsule volume of a stratospheric airship under different pressure differential conditions during the test preparation phase, providing capsule volume measurement data support for airtightness testing. The device mainly consists of a 3D laser scanner, a stitching target sphere, a tripod, a processing terminal, and processing software. It can achieve rapid and high-precision measurement of the shape of large-sized stratospheric airship capsules, and the software automatically calculates the actual capsule volume. Specifically, the 3D laser scanner collects data points from the capsule under test, generating point cloud data; the stitching target sphere serves as a standard common target sphere for stitching data from multiple scanning stations; the tripod is used to mount the scanner; the processing terminal is a mobile workstation used to process the point cloud data collected by the scanner; and the processing software, installed on the processing terminal, processes the collected point cloud data, enabling automatic stitching of multi-station scanning results and calculation of the capsule volume under test. The design technical specifications of the capsule volume measurement device are as follows:

[0105] Effective scanning distance ≥100m;

[0106] Minimum scanning distance ≤ 0.6m;

[0107] Scanning speed ≥ 500,000 points / second;

[0108] Distance measurement error ≤ ±3mm.

[0109] 3) Environmental parameter measurement subsystem

[0110] The environmental parameter measurement subsystem is used to measure and monitor the actual ambient temperature and pressure around the stratospheric airship capsule at the test site throughout the entire process. The subsystem includes multiple distributed ambient temperature and pressure measurement nodes. Each ambient temperature measurement node includes a microcontroller, a LoRa (Long Range Radio) wireless communication unit, and an ambient temperature sensor; each ambient pressure measurement node includes a microcontroller, a LoRa wireless communication unit, and an ambient pressure sensor. All measurement nodes are powered by lithium batteries. Four ambient temperature measurement nodes are deployed, located within the test capsule's hangar in the east, south, west, and north directions, within 10 meters of the capsule's edge, at a height of half the capsule's maximum cross-sectional diameter above the ground. Similarly, four ambient pressure measurement nodes are also deployed within the test capsule's hangar in the east, south, west, and north directions, within 10 meters of the capsule's edge, at a height of half the capsule's maximum cross-sectional diameter above the ground. The arrangement of each measurement node is as follows: Figure 4 and Figure 5 As shown. The design specifications of the environmental parameter measurement subsystem are as follows:

[0111] Ambient temperature sensor: Reference model PT100, measuring range 273~323K, accuracy 0.1K;

[0112] Environmental pressure sensor: Reference model GDPA-10, measuring range 80~110kPa, accuracy 5Pa;

[0113] Ambient temperature measurement node: size no larger than 90*80*24mm, power consumption 0.3W, battery life 7 days;

[0114] Environmental pressure measurement node: size no larger than 110*88*38mm, power consumption 0.3W, battery life 7 days.

[0115] 4) Capsule parameter measurement subsystem

[0116] The capsule parameter measurement subsystem is used to measure and monitor the internal temperature and pressure difference inside and outside the actual capsule of a stratospheric airship throughout the entire testing process. The subsystem includes multiple distributed internal temperature measurement nodes and internal pressure difference measurement nodes. The internal temperature measurement nodes consist of a microcontroller, a LoRa wireless communication unit, and an internal temperature sensor; the internal pressure difference measurement nodes consist of a microcontroller, a LoRa wireless communication unit, and a pressure difference sensor. Ten internal temperature measurement nodes are arranged in two groups, fixed inside the capsule by thin ropes, at 1 / 3 of the capsule's length axially from the head and tail of the capsule, respectively. Each group has five measuring points evenly distributed vertically along the capsule. Four internal pressure difference measurement nodes are arranged in two groups on the capsule surface, at 1 / 3 of the capsule's length axially from the head and tail of the capsule, respectively. Each group has two measuring points located at the top and bottom of the capsule, respectively. The arrangement of each measurement node is as follows: Figure 4 and Figure 5 As shown. The design specifications of the capsule parameter measurement subsystem are as follows:

[0117] Internal temperature sensor of the capsule: Reference model PT100, range 273~323K, accuracy 0.1K;

[0118] Differential pressure sensor inside and outside the capsule: Reference model DDP-2K, range 0~3000Pa, accuracy 1Pa;

[0119] Internal temperature measurement node: size no larger than 90*80*24mm, power consumption 0.3W, battery life 7 days;

[0120] The pressure difference measurement node inside and outside the capsule has a size of no more than 110*88*38mm, a power consumption of 0.3W, and a battery life of 7 days.

[0121] 5) Data transmission and monitoring subsystem

[0122] The data transmission and monitoring subsystem includes a wireless transmission base station, a computer workstation, and data processing and analysis software. This subsystem transmits data from environmental parameter measurement nodes and capsule parameter measurement nodes to the workstation in real time for storage and processes and analyzes the test data. The wireless transmission base station includes a microcontroller, a LoRa wireless communication unit, a real-time clock unit, and a USB virtual serial port unit, powered directly by the computer workstation via USB. Data is transmitted between the wireless transmission base station and the computer workstation via the USB virtual serial port, and between the wireless transmission base station and the environmental and capsule parameter measurement nodes, the LoRa wireless communication protocol (frequency band: 433MHz) is used for transmitting measurement data. The computer workstation is the hardware for storing and processing measurement data. The data processing and analysis software features real-time visualization of various measurement data, capsule airtightness test data processing, and prediction of buoyancy retention capability. The prediction of buoyancy retention capability adopts the stratospheric airship capsule airtightness test method described later. The design technical specifications of the data transmission and monitoring subsystem are as follows:

[0123] Wireless transmission base station dimensions: 90*80*23.8mm;

[0124] Wireless communication range: 1000m without obstruction;

[0125] Data transmission frequency: 1Hz;

[0126] Computer workstation storage capacity: not less than 1TB.

[0127] (3) Test method for airtightness of stratospheric airship capsule

[0128] Reference Figures 6 to 7 Based on the stratospheric airship capsule airtightness testing system, and using a full-size stratospheric airship capsule as the test object, the stratospheric airship capsule airtightness testing steps are as follows:

[0129] 1) Measurement of capsule volume

[0130] Before conducting the airtightness test of the capsule, the volume of the stratospheric airship capsule needs to be measured.

[0131] (a) Using a capsule volume measurement device, a finite element simulation model was used to measure the volume of the capsule under test under different pressure difference conditions. The actual capsule volume was obtained under any pressure difference condition within the range of Pmin to 60% of Pmax, and the curve of the actual capsule volume changing with the pressure difference inside and outside the capsule was fitted. Among them, Pmax is the maximum design working pressure difference of the capsule during the stratospheric airship's stationary period. To avoid damage to the capsule during ground testing, 60% is an additional safety factor; Pmin is the minimum design working pressure difference of the stratospheric airship during its stationary period, generally taken as 300 Pa. The arrangement of the pressure difference sensors is the same as that required for the stratospheric airship capsule airtightness testing system, and the measurement value of the pressure difference sensor at the bottom of the capsule is used as the basis.

[0132] (b) If the volume of the capsule to be tested is large and it is difficult to perform laser scanning measurement, a capsule volume measuring device can be used to measure the volume of a scaled-down capsule with the same material and integrated process. Based on the test data, the finite element simulation model for calculating the capsule volume is corrected, the volume value of the capsule to be tested within the required pressure difference range is derived, and the volume change curve with pressure difference is fitted.

[0133] 2) Encapsulation airtightness test

[0134] (a) Test preparation

[0135] a) The test is conducted in a closed hangar. The test site is prepared and cleaned, and pads and pearl cotton are laid as required. The pads are then cleaned. The test capsule is transferred to the pads, and the capsule is unfolded according to the operating procedures. During the unfolding process, the appearance of the capsule is checked, mainly the welds and the area around the accessories. The capsule inflation port is connected to the inflation pipeline, and the connection is checked for leaks. The inflation pipeline is connected to a high-flow blower, and the capsule is slowly pre-inflated. During the inflation process, the appearance of the capsule is checked. Inflation is stopped when the internal and external pressure difference reaches 50 Pa.

[0136] b) According to the requirements of the stratospheric airship capsule airtightness testing system, arrange internal temperature measurement nodes inside the capsule to be tested, internal and external pressure difference measurement nodes on the capsule surface, and ambient temperature and ambient pressure measurement nodes around the capsule; reconnect the inflation tube, and continue to inflate the capsule with a high-flow fan until the capsule is nearly formed, then turn off the axial flow fan and continue to inflate with a high-pressure fan to 300Pa, then stop inflation; simultaneously, use ropes to fix the capsule to the ground, and use air column support to ensure that the capsule bears minimal load and prevents the capsule from rolling; let it stand for 30 minutes, observe the capsule's condition and pressure difference changes, check for any air leakage sounds, and inspect the capsule's appearance at the same time.

[0137] (b) Testing process

[0138] a) After confirming that the capsule under test has no obvious leakage and that the readings at all measuring points are normal, and after the data at each measuring node stabilizes, conduct the airtightness test of the stratospheric airship capsule. (Refer to...) Figure 8 Four initial pressure differential values ​​were set, with equal pressure differentials between each value. The maximum test pressure differential was 60% of Pmax, and the minimum test pressure differential was 300 Pa. Based on the measurements from the pressure differential sensor at the bottom of the capsule, the capsule's airtightness was tested in ascending order of pressure differential. The continuous testing time under each initial pressure differential condition was no less than 3 hours. The actual internal temperature of the capsule, the actual internal and external pressure differential, the actual ambient temperature, and the actual ambient pressure were measured and recorded at each measuring point, with a data storage interval of 1 second. Airtightness tests under all pressure differential conditions were conducted continuously within the required time, ideally completed within 2 to 3 nights.

[0139] b) The test time is from 23:00 to 5:00 local time. Halogen lamps will not be used for nighttime testing in the test vessel hangar. Unnecessary heat-generating equipment should be turned off in advance to minimize the impact of ambient temperature on the test. During the test, the ambient temperature change should not exceed 5K.

[0140] c) During the test, if the minimum pressure difference at the measuring point of the bladder is less than 200 Pa, record the time and the continuous test time, and record it as a test group. If the continuous test time of this group is less than 3 hours, the bladder needs to be inflated to make up the internal and external pressure difference to the design pressure difference value, and the test should be repeated.

[0141] (c) Post-test processing

[0142] After the airtightness test is completed, the actual test data of the actual internal temperature of the capsule, the actual pressure difference between the inside and outside of the capsule, the actual ambient temperature, and the actual ambient pressure are processed.

[0143] a) The measurement error is judged by observing the test data, and the error is analyzed by the correction method. That is, the sensor is calibrated before the test, and a calibration curve or error table is plotted. After the test, the actual measured value is corrected to obtain effective measurement data. The actual internal temperature of the capsule, the actual pressure difference between the inside and outside of the capsule, the actual ambient temperature, and the actual ambient pressure data are averaged.

[0144] b) Considering the influence of actual ambient temperature and pressure fluctuations during the test, and combining the data on the change of the capsule volume with the actual pressure difference inside and outside the capsule, the ideal gas law is used to obtain the gas mass change curve with time during each set initial pressure difference test period. If the gas mass shows a trend of increasing with time, this set of test data is invalid and cannot be used as the data basis for calculating the equivalent pore size.

[0145] 3) Prediction of buoyancy retention capacity during stationary operation

[0146] (a) Based on the processed valid test data (i.e., actual test data, including actual capsule volume, actual capsule internal temperature, actual capsule internal and external pressure difference, actual ambient temperature, and actual ambient pressure), the equivalent equivalent pore size of the capsule under each initial pressure difference condition is calculated using a gas leakage calculation method based on equivalent pore size. The curve of equivalent pore size versus actual capsule internal and external pressure difference is then fitted. The gas leakage calculation method based on equivalent pore size includes:

[0147] The internal gas leakage of the stratospheric airship capsule structure mainly includes gas infiltration of the capsule material under the action of internal and external pressure difference, gas leakage at the connection parts of the capsule structure, and gas leakage caused by damage to the capsule during processing or transportation. Under the condition that no obvious rupture occurs, the gas leakage of the stratospheric airship capsule is relatively small. In this embodiment, based on actual test data, a calculation method based on equivalent pore size is used to quantitatively evaluate the gas leakage of the capsule.

[0148] The relationship between the gas leakage mass flow rate of the capsule and the equivalent orifice diameter is as follows:

[0149]

[0150] Where μ represents the flow coefficient, ranging from 0.5 to 1.0, and is related to gas viscosity, pressure difference, and pore size; in testing, it can be taken as 1.0. Q d (t) represents the gas leakage mass flow rate at time t, d m (ΔP(t)) represents the equivalent pore size, which is a function of the pressure difference in the bladder, i.e., it is a constant value under any pressure difference condition. P(t) represents the ambient pressure at the current moment, ΔP(t) represents the current pressure difference, T(t) represents the ambient temperature at the current moment, and R... gas This represents the gas constant.

[0151] If the gas leakage is small, the pressure difference between the inside and outside of the capsule will change little over a period of time, and the equivalent pore size of the capsule can be considered constant during this time period. The mass of the leaked gas in the capsule is the mass at the end time t. n The difference between the total mass of the gas and the total mass of the gas at the initial time t0 can be expressed using an integral format as follows:

[0152]

[0153] Substituting into the ideal gas law, we get:

[0154]

[0155] in, This represents the environmental pressure at the initial time t0 within a given time period. Represents the end time t within a time period. n Environmental pressures, This represents the pressure difference between the inside and outside of the cyst at the initial time t0 within a time period. Represents the end time t within a time period. n The pressure difference between the inside and outside of the cyst, This represents the temperature of the gas inside the capsule at the initial time t0 within a given time period. Represents the end time t within a time period. n The internal gas temperature This represents the volume of the vesicle at the initial time t0 within a given time period. Represents the end time t within a time period. n The volume of the cyst, μ represents the flow coefficient, and d m0 This represents the equivalent pore size corresponding to the pressure difference between the inside and outside of the bladder at the initial time t0 within a time period.

[0156] Solving the above equation yields the equivalent pore size under the initial pressure difference of the bladder during this time period:

[0157]

[0158] (b) Based on the data on the variation of capsule volume and equivalent pore size with pressure difference, a gas leakage calculation method based on equivalent pore size is adopted, considering the diurnal temperature and pressure difference variation of the capsule during the stagnation process (the diurnal temperature variation of the capsule interior is as follows). Figure 9 As shown, the pressure difference variation pattern is consistent with it. Daily dynamic iterative calculations of gas leakage are performed, dividing the day and night into phases. Based on this, and combined with the platform's minimum nighttime operating pressure difference design requirements, the theoretical vacancy time is calculated. The specific process is as follows: Figure 10 As shown.

[0159] (c) First, based on the initial stationary design parameters of the stratospheric airship design scheme and flight test scheme, including the ambient pressure, ambient temperature, pressure difference between the inside and outside of the airship, average superheat of the airship (the difference between the average temperature inside the airship and the ambient temperature), and airship volume under the initial stationary conditions, the mass of the gas inside the airship under the initial stationary conditions (i.e., the mass of the gas inside the airship under the initial stationary conditions) is obtained according to the ideal gas law. Figure 10 The initial helium mass is calculated first; then, based on the average superheat and overpressure values ​​(pressure difference between the inside and outside of the capsule) designed during the day, the gas leakage rate and the mass of residual gas inside the capsule during the day are calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Similarly, based on the average superheat and overpressure values ​​(pressure difference between the inside and outside of the capsule) designed at night, the gas leakage rate and the mass of residual gas inside the capsule at night are calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. This yields the gas leakage rate and the mass of residual gas inside the capsule on the first day of buoyancy. This process is repeated, updating the capsule volume, pressure difference between the inside and outside of the capsule, and equivalent orifice diameter based on the mass of residual gas inside the capsule from the previous day, to calculate the gas leakage rate during the day and night of day i, thus obtaining the mass of residual gas inside the capsule on day i. According to the principle of minimum pressure difference for buoyancy-controlled capsules, if the updated nighttime pressure difference between the inside and outside of the capsule on day i is less than the minimum pressure difference required to maintain the capsule's shape, the theoretical buoyancy time is reached, and the buoyancy retention capacity prediction calculation ends. Specifically:

[0160] Under actual stationary flight conditions, the pressure difference between the inside and outside of the capsule is larger during the day and smaller at night. Therefore, the equivalent orifice diameter for gas leakage in the capsule differs between day and night. Formulas are established to calculate the relationship between the gas leakage mass and the equivalent orifice diameter for both daytime and nighttime periods during stationary flight, where P... atm and T atm Given the initial ambient pressure and temperature under stalemate conditions, assume they remain constant during stalemate; ΔT day and ΔP day d represents the diurnal average superheat and overpressure values ​​for any day during the stationary period. day (Δp day The equivalent daytime orifice diameter corresponding to this overpressure value; ΔT night and ΔP night The average superheat and overpressure values ​​at night, d night (Δp night For this overpressure value, the equivalent nighttime orifice diameter is t. day and t night Let the daytime and nighttime be the time of day, from which the daytime and nighttime gas leakage amounts for that day are obtained. The formulas for calculating the daytime and nighttime gas leakage amounts are:

[0161]

[0162]

[0163] The overall design and flight test plans of airships generally specify the technical indicators of the design or test hovering time. This plan obtains the theoretical hovering time through prediction methods, which can be compared with the design technical indicators and serve as the qualification basis for the airtightness test of the airbag. It can also provide a reference for the design, development and flight test of airships.

[0164] In this embodiment, the stratospheric airship capsule airtightness testing system and method use a full-size stratospheric airship capsule structure as the test object. It comprehensively considers gas permeation of the capsule material under internal and external pressure differences, gas leakage at capsule structure connections, and gas leakage caused by damage during processing and transportation. This allows for a comprehensive reflection of the true state of the stratospheric airship capsule, improving the accuracy of stratospheric airship capsule structure airtightness measurement and evaluation. The stratospheric airship capsule airtightness testing system uses wireless transmission for data acquisition, reducing the difficulty of setting up the system, decreasing the error rate in on-site setup, and improving testing efficiency. This provides a reliable testing environment and conditions for evaluating the airtightness performance of stratospheric airship capsules. The stratospheric airship capsule airtightness testing system employs a distributed wireless sensor network to measure the internal temperature, internal and external pressure difference, and ambient temperature and pressure of the capsule. The data transmission frequency of the measurement nodes reaches 1Hz, meaning the time interval for recording and storing data is 1 second. This fully considers the spatial and temporal non-uniformity of the capsule and environmental parameters, improving the overall accuracy of the capsule and environmental parameter measurements and providing more accurate test data support for evaluating the capsule's airtightness performance. The stratospheric airship capsule airtightness testing method comprehensively considers the gas leakage characteristics caused by the capsule material itself, connection points, and material damage. It uses an equivalent pore size to describe and quantify the gas leakage characteristics of the stratospheric airship capsule, and considers the influence of the internal and external pressure difference on the equivalent pore size. During the test, the equivalent pore size values ​​of the capsule under different pressure difference conditions are obtained in segments, basically covering the actual operating pressure difference range of the stratospheric airship capsule, effectively improving the accuracy of the measurement and evaluation of the stratospheric airship capsule's structural airtightness performance. The method for testing the airtightness of stratospheric airship capsules considers the impact of capsule volume changes on airtightness. During the test, a three-dimensional laser scanning device is used to measure the volume of the stratospheric airship capsule, and the volume measurement data is verified based on finite element simulation. The method reveals the variation of capsule volume with internal and external pressure differences, providing a reliable basis for evaluating the capsule's airtightness performance. The method fully considers the influence of ambient temperature and pressure fluctuations on the airtightness measurement. The test is required to be conducted during the period from 23:00 to 5:00 in the morning when ambient temperature and pressure are relatively stable. The test site is a closed hangar to minimize the impact of ambient temperature and pressure. During the test, the ambient temperature variation is required to be no greater than 5K, and data segments showing an increase in gas mass over time calculated from the measurement data are excluded, thus improving the accuracy of the capsule's airtightness performance evaluation.The method for testing the airtightness of stratospheric airship capsules is based on the curve of the equivalent pore size of the capsule changing with the internal and external pressure difference obtained from the test. It takes into account the variation law of parameters such as internal temperature, internal and external pressure difference, and capsule volume under actual stationary flight conditions and their influence on the equivalent pore size of the capsule. It adopts a day-night iterative calculation method to predict and calculate the daily gas leakage and theoretical stationary time of stratospheric airships under stationary conditions. It effectively evaluates the buoyancy maintenance capability of stratospheric airships during stationary flight and provides an important reference for the measurement of airtightness of stratospheric airship capsules and performance improvement.

[0165] This invention also provides a stratospheric airship airbag airtightness testing device, comprising: at least one control processor and a memory for communicating with the at least one control processor.

[0166] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0167] The non-transient software program and instructions required to implement the stratospheric airship capsule airtightness testing method of the above embodiments are stored in memory. When executed by the processor, the stratospheric airship capsule airtightness testing method of the above embodiments is executed, for example, the method described above is executed. Figure 1 The method steps S100 to S800.

[0168] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0169] This invention also provides a computer-readable storage medium storing computer-executable instructions. These instructions are executed by one or more control processors, causing the processors to perform a stratospheric airship capsule airtightness testing method as described in the above-described method embodiments. For example, they can execute the above-described... Figure 1 The functions of steps S100 to S800 in the method.

[0170] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0171] The above is a detailed description of the preferred embodiments of this application. However, the embodiments of this application are not limited to the above-described implementation methods. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the embodiments of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of the embodiments of this application.

Claims

1. A method for testing the airtightness of a stratospheric airship capsule, characterized in that, The method for testing the airtightness of the stratospheric airship capsule includes: Acquire actual test data and initial stationary design parameters for the stratospheric airship capsule; wherein, the actual test data includes actual capsule volume, actual internal capsule temperature, actual internal and external pressure difference, actual ambient temperature, and actual ambient pressure; the initial stationary design parameters include ambient pressure, ambient temperature, internal and external pressure difference, average superheat value, capsule volume, and internal gas mass under initial stationary conditions, wherein the average superheat value includes daytime average superheat value and nighttime average superheat value, wherein the internal and external pressure difference includes daytime internal and external pressure difference and nighttime internal and external pressure difference, and wherein the average superheat value is the difference between the average internal temperature of the capsule and the ambient temperature; Based on the curve of the actual capsule volume changing with the pressure difference inside and outside the actual capsule, the actual capsule internal temperature, the actual capsule internal and external pressure, the actual ambient temperature and the actual ambient pressure, the equivalent pore size of the capsule under different initial pressure difference conditions is calculated based on the principle of mass conservation and the ideal gas law, and the curve of the equivalent pore size changing with the pressure difference of the capsule is obtained by fitting. Based on the actual environmental pressure, the actual internal temperature of the bladder, the actual pressure difference between the inside and outside of the bladder, and the curve of the equivalent pore size changing with the pressure difference of the bladder, the relationship between the gas leakage mass flow rate and the equivalent pore size is constructed. Based on the ambient pressure, ambient temperature, daytime average superheat value, and daytime pressure difference between the inside and outside of the capsule under the initial evacuation conditions, the daytime gas leakage is calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Based on the daytime gas leakage and the initial gas mass inside the capsule, the remaining gas mass inside the capsule during the daytime is calculated. Based on the ambient pressure, ambient temperature, nighttime average superheat value, and nighttime pressure difference between the inside and outside of the capsule under the initial suffocation conditions, the nighttime gas leakage is calculated using the relationship between the gas leakage mass flow rate and the equivalent orifice diameter. Based on the nighttime gas leakage and the daytime residual gas mass inside the capsule, the nighttime residual gas mass inside the capsule is calculated. Based on the mass of the remaining gas inside the capsule at night, the capsule volume, the pressure difference between the inside and outside of the capsule, and the equivalent pore size are updated using the ideal gas law, the curve of the actual capsule volume changing with the actual pressure difference between the inside and outside of the capsule, and the curve of the equivalent pore size changing with the actual pressure difference between the inside and outside of the capsule. Based on the updated capsule volume, pressure difference between inside and outside the capsule, and equivalent pore size, the mass of residual gas inside the capsule at night on the following day is calculated until the updated pressure difference between inside and outside the capsule is less than the preset minimum pressure difference, at which point the theoretical dwell time is reached. Based on the theoretical dwell time, the airtightness test results of the stratospheric airship capsule were obtained.

2. The method for testing the airtightness of a stratospheric airship capsule according to claim 1, characterized in that, The principle of mass conservation and the ideal gas law can be constructed as follows: in, Indicates the initial time within a time period. Environmental pressure, Indicates the end time within a time period Environmental pressures, Indicates the initial time within a time period. The pressure difference between the inside and outside of the cyst, Indicates the end time within a time period The pressure difference between the inside and outside of the cyst, Indicates the initial time within a time period. The internal temperature of the cyst. Indicates the end time within a time period The internal ambient temperature, Indicates the initial time within a time period. The volume of the cyst, Indicates the end time within a time period The volume of the cyst, Indicates the flow coefficient. Indicates the initial time within a time period. The equivalent pore size corresponding to the pressure difference inside and outside the capsule. Indicates the environmental pressure at the current moment. Indicates the current pressure difference. This indicates the current ambient temperature. This represents the gas constant.

3. The method for testing the airtightness of a stratospheric airship capsule according to claim 2, characterized in that, The relationship between gas leakage mass flow rate and equivalent orifice diameter is established as follows: in, The mass flow rate of the gas leak at the current moment. The equivalent orifice diameter corresponding to the current pressure difference. This represents the flow coefficient.

4. The method for testing the airtightness of a stratospheric airship capsule according to claim 1, characterized in that, The daytime gas leakage rate is calculated as follows: in, This represents the environmental pressure under initial resident conditions. This represents the ambient temperature under initial evacuation conditions. This represents the average daytime superheat during the period of stationary airspace. This represents the intra-day pressure difference between the inside and outside of the cyst during a single day of airborne activity. This represents the intra-day pressure difference between the inside and outside of the bladder during the daytime period of stationary airspace. The corresponding daytime equivalent aperture, This indicates the daytime hours during a day spent in the air. Indicates the flow coefficient. This represents the gas constant.

5. The method for testing the airtightness of a stratospheric airship capsule according to claim 1, characterized in that, The nighttime gas leakage rate is calculated as follows: in, This represents the environmental pressure under initial resident conditions. This represents the ambient temperature under initial evacuation conditions. This indicates the average nighttime superheat value during a day of airborne activity. This represents the pressure difference between the inside and outside of the bladder during the nighttime period of airborne activity. This represents the pressure difference between the inside and outside of the bladder during the nighttime period of a single day. The corresponding equivalent aperture at night, This indicates the nighttime hours of a day during an airborne mission. Indicates the flow coefficient. This represents the gas constant.

6. A stratospheric airship airbag airtightness testing system, characterized in that, The stratospheric airship airlock airtightness testing system includes: A capsule inflation device, which is connected to the stratospheric airship capsule and is used to inflate the stratospheric airship capsule. A capsule volume measuring device is used to measure the actual capsule volume of the stratospheric airship under different pressure difference conditions. An environmental parameter measurement subsystem is installed around the stratospheric airship capsule to measure the actual ambient temperature and actual ambient pressure around the stratospheric airship capsule. A capsule parameter measurement subsystem is installed on the surface and inside the capsule of the stratospheric airship to measure the actual internal temperature and the actual pressure difference between the inside and outside of the capsule. A data transmission and storage subsystem is provided, which is communicatively connected to the environmental parameter measurement subsystem and the capsule parameter measurement subsystem. This subsystem is used to transmit measurement data from the environmental parameter measurement subsystem and the capsule parameter measurement subsystem to a workstation for storage in real time. The measurement data is then processed and analyzed, and the equivalent orifice diameter and theoretical dwell time under different pressure differential conditions are calculated using the stratospheric airship capsule airtightness testing method described in any one of claims 1 to 5.

7. The stratospheric airship airbag airtightness testing system according to claim 6, characterized in that, The capsule volume measurement device includes a 3D laser scanner, a stitching target sphere, a tripod, a processing terminal, and processing software. The 3D laser scanner is used to collect data points from the stratospheric airship capsule and generate point cloud data. The stitching target sphere serves as a standard common target sphere for multi-station scanning and data stitching. The tripod is used to mount the scanner. The processing terminal is a mobile workstation used to process the point cloud data collected by the 3D laser scanner. The processing software is installed in the processing terminal and used to process the point cloud data.

8. The stratospheric airship airbag airtightness testing system according to claim 6, characterized in that, The stratospheric airship capsule airtightness testing system uses distributed wireless sensors to measure the actual internal temperature of the capsule, the actual internal and external pressure difference of the capsule, the actual ambient temperature, and the actual ambient pressure.

9. A device for testing the airtightness of a stratospheric airship capsule, characterized in that, It includes at least one control processor and a memory for communicatively connecting to the at least one control processor; the memory stores instructions executable by the at least one control processor, which, when executed by the at least one control processor, enable the at least one control processor to perform the stratospheric airship airtightness test method as described in any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the stratospheric airship airbag airtightness testing method as described in any one of claims 1 to 5.

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