Density measurement method for strong dynamic load high enthalpy environment

Abstract

The invention discloses a strong dynamic load high enthalpy environment density measurement method. The method comprises the following steps: measuring the flow velocity of strong dynamic carrier gas flow, and measuring heating heat flow; based on the enthalpy change in the heat transfer process of the heating heat flow, the enthalpy value of the strong dynamic load environment is obtained through calculation, and the dynamic pressure condition in the strong dynamic load environment is obtained through calculation by means of the total enthalpy and the airflow velocity; and based on the dynamic pressure condition, calculating to obtain a density parameter of the strong dynamic load environment. After the airflow velocity of the strong dynamic load environment is measured in a non-contact manner, the dynamic pressure condition is established by measuring the heating heat flow and calculating the enthalpy value so as to represent the dynamic pressure of the strong dynamic load environment, the density parameter of the strong dynamic load environment is calculated based on the dynamic pressure condition, and the enthalpy value is subjected to experiment and calculation simulation correction, so that the density of the strong dynamic load environment is calculated. The measurement precision of density parameters in the strong dynamic load environment is improved, and the problems in density measurement in the strong dynamic load environment are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of strong dynamic load environment simulation, and in particular to a method for measuring density in a strong dynamic load high enthalpy environment. Background Art

[0002] Strong dynamic load environments are extremely complex and have strong energy impacts. There are usually strong energy release processes such as detonation, explosion, high-speed impact, and fast flight, which instantly produce extremely high pressure, temperature, or speed changes. It may cause strong shock waves, exert huge forces and impulses on surrounding objects, and make objects bear loads far beyond their static bearing capacity; it may also cause continuous forces and torques, causing structures or mechanisms to have large spatial displacements and movements. The physical process of strong dynamic load environments involves multiphase flow and complex chemical reactions. At the same time, the performance of materials will be significantly deformed, and even the structure will move and flip, which will have a profound impact on mechanical response and failure mode.

[0003] The combined drive of high-pressure air and energetic medium is a typical way to generate a strong dynamic load environment, but the computational simulation of the strong dynamic load environment is quite difficult, and the complex structural evolution in the flow field may even cause damage to the instrument, and even make it difficult to accurately control the timing of system control, measurement and acquisition during the experiment, which makes it extremely difficult to measure and evaluate the state of the strong dynamic load environment, and also causes large measurement deviations. In addition, due to the complexity of the strong dynamic load experiment, the measurement methods and number of sensors are relatively insufficient, and the data information obtained is very limited. For example, the traditional measurement through Pitot pressure is difficult to solve the problem for high enthalpy conditions.

[0004] Therefore, the existing method of measuring the strong dynamic load environment through the Pitot pressure is difficult to apply to high enthalpy conditions and it is difficult to accurately obtain the density parameters of the strong dynamic load environment, which makes it extremely difficult to measure and evaluate the state of the strong dynamic load environment. Summary of the invention

[0005] The purpose of the present invention is to provide a method for measuring density in a high dynamic load and high enthalpy environment, so as to solve the technical problem that the method of measuring the high dynamic load environment by Pitot pressure in the prior art is difficult to apply to high enthalpy conditions and difficult to accurately obtain the density parameters of the high dynamic load environment, thereby causing great difficulty in the state measurement and evaluation of the high dynamic load environment.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A method for measuring density in a high dynamic load and high enthalpy environment comprises the following steps:

[0008] Step 100, using non-contact measurement to obtain the flow rate of the strong carrier gas flow, and using a heat flow sensor to measure and obtain the heating heat flow;

[0009] Step 200: According to the basic principle of heat flow transfer, the enthalpy value of the strong dynamic load environment is calculated using the heating heat flow, and the enthalpy value of the strong dynamic load environment is corrected by experiments and calculation simulations;

[0010] Step 300: After correction, based on the enthalpy value of the strong dynamic load environment and the airflow velocity, the dynamic pressure condition under the strong dynamic load environment is calculated, and based on the dynamic pressure condition, the density parameter of the strong dynamic load environment is calculated.

[0011] As a preferred solution of the present invention, in step 100, the specific method of obtaining the flow rate of the strong carrier gas flow by non-contact measurement is:

[0012] Adding molecules to the airstream induces fluorescent labeling;

[0013] Non-contact measurement of airflow to obtain spatial movement distance and exposure time difference;

[0014] The airflow velocity is calculated based on the spatial moving distance and the exposure time difference.

[0015] As a preferred solution of the present invention, in step 100, the specific method of measuring and obtaining the heating heat flow using the heat flow sensor is:

[0016] Coaxial thermocouples are used to directly measure surface temperature changes over time;

[0017] The surface heating heat flux is directly calculated based on the one-dimensional semi-infinite body heat conduction theory formula.

[0018] As a preferred solution of the present invention, in step 200, the specific method of calculating the enthalpy value of the strong dynamic load environment is:

[0019] According to the formula:

[0020] q w =cρ(H0-H w );

[0021] Obtain the total enthalpy of the strong dynamic load environment, and get:

[0022]

[0023] Among them, q w is the heating heat flow, c is the heat transfer factor, H0 is the enthalpy value of the strong dynamic load environment, H w is the wall enthalpy; ρ is the density;

[0024] Based on experimental measurement and numerical simulation, the heat transfer factor is corrected, and the specific correction method is as follows:

[0025] Calculate the heat transfer factor c for each experiment;

[0026] The polynomial fitting was performed on the results of multiple experiments to obtain the relationship of heat transfer factor c;

[0027] Each heat transfer factor c is corrected according to the relationship.

[0028] As a preferred solution of the present invention, in step 300, the specific method of calculating and obtaining the dynamic pressure condition under the strong dynamic load environment is:

[0029] Under strong dynamic load conditions:

[0030]

[0031] Among them, the measured ρH0 approximately represents the dynamic pressure condition of the strong dynamic load environment;

[0032] Where u is the air velocity, is the dynamic pressure.

[0033] As a preferred solution of the present invention, in step 300, the specific method of calculating and obtaining the density parameter of the strong dynamic load environment is:

[0034] Determine the density parameter ρ of the strong dynamic load environment:

[0035]

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention adopts non-contact measurement of the air flow velocity in a strong dynamic load environment, and then establishes a dynamic pressure condition by measuring the heating heat flux and enthalpy calculation to characterize the dynamic pressure of the strong dynamic load environment, and calculates the density parameters of the strong dynamic load environment based on the dynamic pressure condition. The enthalpy value is corrected by experiments and calculation simulation to improve the measurement accuracy of the density parameters of the strong dynamic load environment, and effectively solves the difficult problem in density measurement in a strong dynamic load environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0039] Figure 1 A schematic flow chart of a method for measuring density in a high dynamic load and high enthalpy environment provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, the present invention provides a method for measuring density in a strong dynamic load high enthalpy environment, comprising the following steps:

[0042] Step 100, using non-contact measurement to obtain the flow rate of the strong carrier gas flow, and using a heat flow sensor to measure and obtain the heating heat flow;

[0043] Step 200: According to the basic principle of heat flow transfer, the enthalpy value of the strong dynamic load environment is calculated using the heating heat flow, and the enthalpy value of the strong dynamic load environment is corrected by experiments and calculation simulations;

[0044] Step 300: After correction, based on the enthalpy value of the strong dynamic load environment and the airflow velocity, the dynamic pressure condition under the strong dynamic load environment is calculated, and based on the dynamic pressure condition, the density parameter of the strong dynamic load environment is calculated.

[0045] The density measurement method of a high dynamic load and high enthalpy environment of the present invention mainly adopts a non-contact measurement method to measure the airflow velocity of the high dynamic load environment and adopts a heat flow sensor to measure the heating heat, thereby calculating the enthalpy value of the high dynamic load environment, and correcting the enthalpy value of the high dynamic load environment through a large number of experiments and computational simulations, thereby establishing an accurate relationship between the enthalpy value and the dynamic pressure, that is, the dynamic pressure condition, and calculating the density parameters of the high dynamic load environment based on the dynamic pressure condition to solve the problem of density measurement in the high dynamic load environment.

[0046] The density parameter measurement method for a strong dynamic load environment proposed in the present invention effectively solves the problem of density measurement in a strong dynamic load environment by adopting innovative technical means such as optical non-contact measurement of air flow velocity, homemade heat flow sensor to measure heating heat flow, calculation of enthalpy value and establishment of relationship with dynamic pressure, correction of heat transfer factor and final determination of density parameter. This method can ensure accuracy and reliability, has good application prospects, and provides a robust measurement solution for scientific research and engineering applications related to strong dynamic load environments, which is expected to promote further development in the field of research on strong dynamic load environments.

[0047] In step 100, the specific method of obtaining the flow rate of the strong carrier gas flow by non-contact measurement is:

[0048] Adding molecules to the airstream induces fluorescent labeling;

[0049] Non-contact measurement of airflow to obtain spatial movement distance and exposure time difference;

[0050] The airflow velocity is calculated based on the spatial moving distance and the exposure time difference.

[0051] Molecular induced fluorescence labeling technology is an effective method. In a strong dynamic load environment, specific fluorescent labeling molecules are injected into the airflow, and the movement of the airflow is tracked by the fluorescence emitted by these molecules after being irradiated with excitation light. The airflow velocity can be calculated based on the moving distance of the fluorescent labeling molecules in space and the exposure time difference.

[0052] This measurement method has significant advantages. First, it is a non-contact measurement method that does not interfere with the airflow and can obtain accurate velocity information without affecting the strong dynamic load environment. Second, the molecular induced fluorescence labeling technology has high spatial resolution and temporal resolution, and can accurately capture small changes in the airflow, which is of great significance for studying high-speed airflow motion under strong dynamic load environments.

[0053] In actual operation, it is necessary to precisely control the parameters of the excitation light and the concentration of the fluorescent marker molecules to ensure the accuracy of the measurement. At the same time, it is also necessary to consider the collection and processing methods of the fluorescence signal to improve the accuracy of the measurement.

[0054] In step 100, the specific method of using the heat flow sensor to measure and obtain the heating heat flow is:

[0055] Coaxial thermocouples are used to directly measure surface temperature changes over time;

[0056] The surface heating heat flux is directly calculated based on the one-dimensional semi-infinite body heat conduction theory formula.

[0057] In order to obtain the heat flow of the measuring device under the strong dynamic load environment, the present invention adopts a coaxial thermocouple for direct measurement. The coaxial thermocouple has a special structure and material, and can accurately measure the heat flow under the strong dynamic load environment.

[0058] In a strong dynamic load environment, due to the release of energy and the change of the flow field, the measuring device will be strongly heated, and the size of the heat flow directly reflects the energy transfer characteristics of the environment. The design of the heat flow sensor needs to consider many factors. For example, the material of the sensor must be able to withstand the impact of high temperature, high pressure and high-speed airflow in a strong dynamic load environment, and at the same time have good thermal conductivity to accurately measure the heat flow. The structural design of the sensor must ensure that it can be well combined with the measuring device and can effectively isolate external interference.

[0059] Through this heat flow sensor, the heating heat flow of the measuring device caused by the strong dynamic load environment can be directly measured, providing important data support for subsequent environmental parameter calculations.

[0060] In step 200, the specific method of calculating the enthalpy value of the strong dynamic load environment is:

[0061] According to the formula:

[0062] q w =cρ(H0-H w );

[0063] Obtain the total enthalpy of the strong dynamic load environment, and get:

[0064]

[0065] Among them, q w is the heating heat flow, c is the heat transfer factor, H0 is, H w is the wall enthalpy; ρ is the density;

[0066] Based on experimental measurement and numerical simulation, the heat transfer factor is corrected, and the specific correction method is as follows:

[0067] Calculate the heat transfer factor C for each experiment;

[0068] The polynomial fitting was performed on the results of multiple experiments to obtain the relationship of heat transfer factor C;

[0069] Each heat transfer factor C is corrected according to the relationship.

[0070] According to the basic principle of heat flow transfer, the present invention uses the formula: q w =cρ(H0-H w ), determine the enthalpy value of the strong dynamic load environment.

[0071] In this formula, c is the heat transfer factor, ρ is the density, H0 is the enthalpy value of the strong dynamic load environment, and H w is the wall enthalpy.

[0072] In general, the wall enthalpy corresponds to room temperature conditions. Under strong dynamic load conditions, it can be properly treated according to the specific situation, or even ignored in some cases. The heating heat flux q w , combined with the known heat transfer factor c and density ρ, the value of the total enthalpy H0 of the strong dynamic load environment can be calculated.

[0073] This calculation process requires accurate measurement data and precise determination of the heat transfer factor c, while taking into account the changes in wall enthalpy under different experimental conditions to ensure the accuracy of the enthalpy calculation.

[0074] In order to improve the accuracy of measurement and data processing, the present invention corrects the heat transfer factor c based on a large number of experimental, numerical simulation and other results. The heat transfer factor c may change under different experimental conditions and is affected by many factors, such as the turbulence degree of the flow field, changes in the composition of the material, and fluctuations in temperature and pressure.

[0075] By analyzing a large amount of experimental data and numerical simulation results, we can determine the influence of these factors on the heat transfer factor, and thus establish a corresponding correction model. In the actual measurement process, this correction model is used to make real-time corrections to the heat transfer factor c to improve the accuracy and reliability of the measurement results.

[0076] In step 300, the specific method of calculating and obtaining the dynamic pressure condition under the strong dynamic load environment is:

[0077] Under strong dynamic load conditions:

[0078]

[0079] Among them, the measured ρH0 approximately represents the dynamic pressure condition of the strong dynamic load environment;

[0080] Where u is the air velocity, is the dynamic pressure.

[0081] Under strong dynamic load conditions, there is This means that the value of ρH0 obtained by previous measurement and calculation can approximately characterize the dynamic pressure condition of the strong dynamic load environment. The establishment of this relationship provides an important basis for further understanding the mechanical properties of the strong dynamic load environment. By linking the enthalpy value with the dynamic pressure condition, the physical state of the strong dynamic load environment can be more comprehensively described, providing richer information for experimental research and engineering applications.

[0082] In step 300, the specific method of calculating and obtaining the density parameter of the strong dynamic load environment is:

[0083] Determine the density parameter ρ of the strong dynamic load environment:

[0084]

[0085] Based on the above measurements and calculations, the present invention uses the formula: Determine the density parameters of the strong dynamic load environment. Through the optical non-contact measurement of air flow velocity, the measurement of heating heat flux, the calculation of enthalpy value and the correction of heat transfer factor in the previous steps, sufficient information has been obtained to accurately calculate the density parameters.

[0086] This method determines the density parameters by comprehensively measuring multiple key physical quantities, overcoming the problem that traditional methods are difficult to accurately measure density under strong dynamic load environments. It makes full use of the synergy between different measurement methods, transforms the complex measurement problem of strong dynamic load environments into a solvable multi-step measurement and calculation process, thereby realizing indirect measurement of density parameters.

[0087] Specifically, the present invention abandons the limitations of the traditional single measurement method, adopts multiple measurement methods to measure key physical quantities, including air flow velocity, heating heat flow, etc., and then integrates these measurement results to obtain the strong dynamic load environment parameters. This comprehensive measurement method can more comprehensively reflect the complex physical characteristics of the strong dynamic load environment, and overcomes the measurement deviation problem caused by insufficient single measurement information in the traditional method.

[0088] Heat flow sensor and enthalpy calculation to characterize dynamic pressure. A self-made heat flow sensor is designed to directly measure the heat flow of the strong dynamic load environment on the measuring device, and the enthalpy value is calculated through a specific formula. This method solves the measurement difficulties of traditional measurement methods under high enthalpy conditions, and can accurately obtain enthalpy information in strong dynamic load environments, providing key data for further analysis of environmental parameters. By establishing an approximate relationship between enthalpy and dynamic pressure conditions, a new idea is provided for dynamic pressure measurement in strong dynamic load environments.

[0089] Data-driven heat transfer factor correction. The heat transfer factor is corrected based on a large number of experimental and numerical simulation results. This is a data-driven optimization method. By considering the influence of multiple complex factors on the heat transfer factor, a correction model is established to improve the accuracy of measurement and data processing. This method can effectively cope with the complexity and variability of strong dynamic load environments and ensure the accuracy and reliability of measurement results.

[0090] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A method for measuring density in a high dynamic load and high enthalpy environment, characterized in that: The steps include: Step 100, using non-contact measurement to obtain the flow rate of the strong carrier gas flow, and using a heat flow sensor to measure and obtain the heating heat flow; Step 200: According to the basic principle of heat flow transfer, the enthalpy value of the strong dynamic load environment is calculated using the heating heat flow, and the enthalpy value of the strong dynamic load environment is corrected by experiments and calculation simulations; Step 300: After correction, based on the enthalpy value of the strong dynamic load environment and the airflow velocity, the dynamic pressure condition under the strong dynamic load environment is calculated, and based on the dynamic pressure condition, the density parameter of the strong dynamic load environment is calculated.

2. The method for measuring density in a high dynamic load and high enthalpy environment according to claim 1 is characterized in that: In step 100, the specific method of obtaining the flow rate of the strong carrier gas flow by non-contact measurement is: Adding molecules to the airstream induces fluorescent labeling; Non-contact measurement of airflow to obtain spatial movement distance and exposure time difference; The airflow velocity is calculated based on the spatial moving distance and the exposure time difference.

3. The method for measuring density in a high dynamic load and high enthalpy environment according to claim 1 is characterized in that: In step 100, the specific method of using the heat flow sensor to measure and obtain the heating heat flow is: Coaxial thermocouples are used to directly measure surface temperature changes over time; The surface heating heat flux is directly calculated based on the one-dimensional semi-infinite body heat conduction theory formula.

4. The method for measuring density in a high dynamic load and high enthalpy environment according to claim 1 is characterized in that: In step 200, the specific method of calculating the enthalpy value of the strong dynamic load environment is: According to the formula: q w =cρ(H0-H w ); Obtain the total enthalpy of the strong dynamic load environment, and get: Among them, q w is the heating heat flow, c is the heat transfer factor, H0 is the enthalpy value of the strong dynamic load environment, H w is the wall enthalpy; ρ is the density; Based on experimental measurement and numerical simulation, the heat transfer factor is corrected, and the specific correction method is as follows: Calculate the heat transfer factor c for each experiment; The polynomial fitting of multiple experimental results was performed to obtain the relationship of heat transfer factor c; Each heat transfer factor c is corrected according to the relationship.

5. The method for measuring density in a high dynamic load and high enthalpy environment according to claim 3 is characterized in that: In step 300, the specific method of calculating and obtaining the dynamic pressure condition under the strong dynamic load environment is: Under strong dynamic load conditions: Among them, the measured ρH0 approximately represents the dynamic pressure condition of the strong dynamic load environment; Where u is the air velocity, is the dynamic pressure.

6. The method for measuring density in a high dynamic load and high enthalpy environment according to claim 3 is characterized in that: In step 300, the specific method of calculating and obtaining the density parameter of the strong dynamic load environment is: Determine the density parameter ρ of the strong dynamic load environment:

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