Method and system for evaluating upper-stage transverse rotational inertia of liquid rocket

Abstract

The invention relates to the technical field of overall design of carrier rockets, and discloses a method and system for evaluating upper-stage transverse rotational inertia of a liquid rocket, and the method comprises the steps: carrying out the CFD simulation calculation of a propellant storage tank based on the flight process of the liquid rocket, and obtaining an acting moment value of a propellant on the storage tank; the acting moment of the propellant on the storage box is converted, and the transverse rotational inertia of the propellant is obtained; and adding the transverse rotational inertia of the propellant and the transverse rotational inertia of the solid part to obtain an evaluation result of the upper stage transverse rotational inertia of the liquid rocket. According to the embodiment of the invention, the transverse rotational inertia reduction caused by the flowing of the propellant is considered, the transverse rotational inertia of the propellant is obtained through the CFD calculation result, and then the attitude control and separation simulation specialty is provided for scheme design, so that the response characteristics of the upper stage under the attitude interference can be reflected more accurately; and accurate parameter support is provided for primary and secondary separation scheme design and attitude control scheme design.

Description

Technical Field

[0001] The present invention relates to the technical field of overall launch vehicle design, and in particular to a method and system for evaluating the lateral moment of inertia of a liquid rocket upper stage. Background Art

[0002] The upper stage of a liquid rocket is a relatively independent one or more stages added to the basic stage rocket. It can further accelerate the payload and send it into a higher orbit or a farther space position, greatly improving the carrying capacity of the entire rocket system. Taking the second stage of a two-stage rocket as an example, the lateral moment of inertia of the second stage is an important parameter that affects the attitude control of the second stage flight phase and the control accuracy of the first and second stage separation process. In the traditional method of calculating the lateral moment of inertia of liquid rockets (refer to "Q1080A-97 Liquid Rocket Mass, Center of Mass and Moment of Inertia Calculation Method"), the axial moment of inertia brought by the propellant is determined to have no effect on the rolling control of the rocket, and the lateral moment of inertia brought by the propellant is considered according to the structural mass. In fact, the propellant will also produce a certain friction force on the box wall when rotating axially, and part of the axial moment of inertia should be considered; when rotating laterally, flow will occur inside the propellant, and it should not be considered entirely according to the rigid structural mass.

[0003] With regard to the current method of calculating the lateral moment of inertia of propellants, in the first-stage flight phase, since the center of mass of the rocket is generally at the first stage, whether the flow properties of the second-stage propellant's moment of inertia are taken into account does not have a significant impact; in the second-stage flight phase, the center of mass of the rocket is located near the tank. When subject to lateral disturbances, part of the propellant will flow with the center of mass as the center of rotation. Therefore, the moment of inertia it brings will be far less than when it is considered based on the structural mass. That is, the actual lateral moment of inertia of the rocket will be smaller than the theoretical value.

[0004] Regarding the above deviations, taking the first and second stage separation design as an example, under the same attitude disturbance (failure of a single separation spring, etc.), due to the smaller lateral rotational inertia of the actual rocket, the attitude change of the second stage during the separation process is greater, increasing the risk of collision between the first and second stages during the separation process. Summary of the invention

[0005] In view of this, the present invention provides a method and system for evaluating the lateral moment of inertia of a liquid rocket upper stage, so as to solve the problem of poor accuracy in calculating the lateral moment of inertia of a liquid rocket upper stage.

[0006] In a first aspect, the present invention provides a method for evaluating the lateral moment of inertia of a liquid rocket upper stage, the method comprising:

[0007] Based on the liquid rocket flight process, the CFD simulation calculation of the propellant tank is carried out to obtain the torque value of the propellant on the tank;

[0008] Convert the torque of the propellant on the tank to obtain the lateral moment of inertia of the propellant;

[0009] The lateral moment of inertia of the propellant is added to the lateral moment of inertia of the solid portion to arrive at an estimate of the lateral moment of inertia of the liquid rocket upper stage.

[0010] The method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket provided in an embodiment of the present invention takes into account the reduction in lateral moment of inertia caused by the flow of the propellant, obtains the lateral moment of inertia of the propellant through CFD calculation results, and finally adds the lateral moment of inertia of the propellant to the lateral moment of inertia of the solid part to obtain an evaluation result of the lateral moment of inertia of the upper stage of the liquid rocket, thereby providing attitude control and separation simulation professionals for scheme design. Compared with the existing method of calculating all based on solids, it can more accurately reflect the response characteristics of the upper stage under attitude disturbance, and provide accurate parameter support for the first and second stage separation scheme design and attitude control scheme design.

[0011] In an optional embodiment, CFD simulation calculation is performed on the propellant tank based on the liquid rocket flight process, including:

[0012] Obtain a three-dimensional model of the liquid rocket propellant tank and its slosh plate arrangement;

[0013] Set the boundary conditions of CFD simulation based on the actual state of liquid rocket flight;

[0014] A CFD fluid simulation calculation of the propellant tank is performed based on the three-dimensional model and the boundary conditions.

[0015] In an optional implementation, the boundary conditions of the CFD simulation include:

[0016] Axial overload, propellant liquid level, and angular acceleration field caused by separation or attitude control similar to those during liquid rocket flight.

[0017] The boundary conditions set in the embodiment of the present invention take into account the dynamic changes of the rocket during separation or attitude control, and can truly reflect the stress conditions of the liquid rocket in flight, so that the simulation can capture the flow behavior of the propellant under complex angular acceleration, and make the simulation results closer to the flow and force performance of the propellant in the tank under actual flight conditions, accurately reflect the consumption of propellant during flight, make the simulation more consistent with the actual flight state, and improve the credibility of the simulation results.

[0018] In an optional implementation, the conversion based on the torque acting on the tank by the propellant to obtain the lateral moment of inertia of the propellant includes:

[0019] Get the corresponding formula between torque and moment of inertia:

[0020] T = Iy × w;

[0021] Where: T represents torque, Iy represents moment of inertia, and w represents angular acceleration;

[0022] The torque of each propellant on the tank obtained by simulation and the angular acceleration at the time of separation or attitude change are substituted into the corresponding relationship formula to obtain the lateral moment of inertia of each propellant at the corresponding moment; the sum of the lateral moments of inertia of each propellant is taken as the lateral moment of inertia of the propellant.

[0023] There are usually multiple propellants in a rocket, which act together on the tank and affect the rotation characteristics of the rocket. The embodiment of the present invention adds the lateral rotational inertia of each propellant to obtain the lateral rotational inertia of the entire propellant system, and obtains a more accurate lateral rotational inertia of the propellant, providing reliable data support for the design and performance analysis of the rocket, thereby more comprehensively evaluating the rotation performance of the rocket. Taking the rotational inertia of each propellant into consideration, the influence of the propellant system on the overall rotation performance of the rocket can be comprehensively evaluated, providing guidance for improving the stability and reliability of the rocket.

[0024] In an optional embodiment, the step of adding the lateral moment of inertia of the propellant to the lateral moment of inertia of the solid portion to obtain an evaluation result of the lateral moment of inertia of the liquid rocket upper stage comprises:

[0025] The lateral moment of inertia of the propellant, the lateral moment of inertia generated by the fairing, and the lateral moment of inertia generated by the axis shift are added together to obtain the lateral moment of inertia of the liquid rocket upper stage.

[0026] The embodiment of the present invention can comprehensively and accurately reflect the overall rotation characteristics of the upper stage by adding the lateral rotational inertia generated by different parts, which helps engineers to have a deeper understanding of the dynamic behavior of the rocket under various working conditions, and provides a more reliable basis for design and optimization. By accurately calculating the lateral rotational inertia of the liquid rocket upper stage, potential problems and risks can be predicted in advance.

[0027] In a second aspect, the present invention provides a liquid rocket upper stage lateral moment of inertia assessment system, the system comprising:

[0028] The simulation module is used to perform CFD simulation calculations on the propellant tank based on the liquid rocket flight process to obtain the torque value of the propellant on the tank;

[0029] A propellant transverse moment of inertia calculation module, used to convert the torque acting on the tank by the propellant to obtain the propellant's transverse moment of inertia;

[0030] The evaluation result output module is used to add the lateral rotational inertia of the propellant and the lateral rotational inertia of the solid part to obtain the evaluation result of the lateral rotational inertia of the liquid rocket upper stage.

[0031] In one embodiment, the simulation module includes:

[0032] A three-dimensional model acquisition unit, used to acquire a three-dimensional model of a liquid rocket propellant tank and an arrangement of its anti-sway plates;

[0033] Boundary adjustment setting unit, used to set the boundary conditions of CFD simulation based on the real state of liquid rocket flight;

[0034] A simulation calculation unit is used to perform CFD fluid simulation calculation of the propellant tank based on the three-dimensional model and the boundary conditions.

[0035] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket according to the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0036] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket according to the first aspect or any corresponding embodiment thereof.

[0037] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, wherein the computer instructions are used to enable a computer to execute the method for evaluating the lateral rotational inertia of the upper stage of a liquid rocket according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 is a schematic flow chart of a method for evaluating the lateral moment of inertia of a liquid rocket upper stage according to an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of a three-dimensional model of a propellant tank and an anti-slosh plate arrangement thereof according to an embodiment of the present invention;

[0041] Figure 3 is a three-axis acceleration curve of a flight simulation according to an embodiment of the present invention;

[0042] Figure 4 is a posture change excitation curve used in simulation according to an embodiment of the present invention;

[0043] Figure 5 (a) is a time-dependent trend of the torque acting in the Z direction according to an embodiment of the present invention;

[0044] Figure 5 (b) is the variation trend of the lateral force excitation over time according to an embodiment of the present invention

[0045] Figure 6 (a) is the liquid flow rate and overall shape before being excited according to an embodiment of the present invention;

[0046] Figure 6 (b) is the flow velocity and overall flow velocity shape after being excited according to an embodiment of the present invention;

[0047] Figure 7 It is a schematic diagram comparing the changes in the moment of inertia of liquid and solid after they are sent into rotation;

[0048] Figure 8 is a structural block diagram of a liquid rocket upper stage lateral moment of inertia evaluation system according to an embodiment of the present invention;

[0049] Fig. 9 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0051] With regard to the current method of calculating the lateral moment of inertia of propellants, in the first-stage flight phase, since the center of mass of the rocket is generally at the first stage, whether the flow properties of the second-stage propellant's moment of inertia are taken into account does not have a significant impact; in the second-stage flight phase, the center of mass of the rocket is located near the tank. When subject to lateral disturbances, part of the propellant will flow with the center of mass as the center of rotation. Therefore, the moment of inertia it brings will be far less than when it is considered based on the structural mass. That is, the actual lateral moment of inertia of the rocket will be smaller than the theoretical value.

[0052] Regarding the above deviations, taking the first and second stage separation design as an example, under the same attitude disturbance (failure of a single separation spring, etc.), due to the smaller lateral rotational inertia of the actual rocket, the attitude change of the second stage during the separation process is greater, increasing the risk of collision between the first and second stages during the separation process.

[0053] To avoid the above risks, this method will calculate the lateral rotational inertia brought by the second-stage propellant through CFD simulation, optimize the value of the lateral rotational inertia of the second-stage flight stage rocket in the original data, and solve the problem that the test is difficult to cover in a weightless environment.

[0054] Figure 1 is a flow chart of a method for evaluating the lateral moment of inertia of a liquid rocket upper stage according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0055] Step S101, based on the liquid rocket flight process, a CFD simulation calculation of the propellant tank is performed to obtain the torque value of the propellant on the tank. Specifically, step S101 includes the following steps:

[0056] Step S1011: obtaining a three-dimensional model of a liquid rocket propellant tank and its anti-sway plate arrangement;

[0057] Specifically, the anti-sway plate is modeled as a surface, and the tank is modeled as a solid. According to the design drawings or technical parameters of the actual liquid rocket propellant tank, the shape (such as cylindrical, spherical, etc.), size (diameter, height, etc.) of the tank and the position, shape and size of the anti-sway plate are clarified. Use professional 3D modeling software such as SolidWorks, CATIA, Pro / Engineer, etc. First, create the main structure of the tank. You can build the basic shape through stretching, rotation, scanning and other operations, and then add the anti-sway plate. You can represent the anti-sway plate by creating the corresponding geometric body inside the tank. Make sure that the connection between the anti-sway plate and the tank is reasonable, and there will be no interference or unreasonable gaps. Refine and adjust the model, such as adding fillets and chamfers, to improve the authenticity and accuracy of the model. Figure 2 As shown, the front and rear bottom areas are the tank body, and the annular and semicircular planes in the figure are anti-sway plates.

[0058] Step S1012: Setting the boundary conditions of the CFD simulation based on the actual state of the liquid rocket during flight.

[0059] The boundary conditions set in the embodiment of the present invention include: an axial overload similar to that in the flight of a liquid rocket (can be determined by consulting relevant technical information or flight data, usually the overload that can be generated by the separation energy source is selected, such as 0.01g), the propellant liquid level (usually the initial height of the unconsumed liquid level, the liquid level of the propellant in the tank is determined according to the actual situation. The specific value can be obtained by measurement or calculation), and the angular acceleration field generated by separation / attitude control (can be determined by analyzing the motion equation of the rocket or flight data, usually the overload that can be generated by the separation energy source is selected, such as 0.01rad / s). Figure 3 The following is the flight simulation three-axis acceleration curve (corresponding to axial overload), as shown in Figure 4 The attitude change excitation curve used in the simulation is shown (corresponding to the angular acceleration field generated by separation / attitude control).

[0060] The boundary conditions set in the embodiment of the present invention take into account the dynamic changes of the rocket during separation or attitude control, and can truly reflect the stress conditions of the liquid rocket in flight, so that the simulation can capture the flow behavior of the propellant under complex angular acceleration, and make the simulation results closer to the flow and force performance of the propellant in the tank under actual flight conditions, accurately reflect the consumption of propellant during flight, make the simulation more consistent with the actual flight state, and improve the credibility of the simulation results.

[0061] Step S1013: Perform CFD fluid simulation calculation of the propellant tank based on the three-dimensional model and boundary conditions.

[0062] In practical applications, there are many professional CFD simulation software to choose from, such as ANSYS Fluent, CFX, STAR-CCM+, etc. These software have powerful fluid simulation functions and can handle complex flow problems.

[0063] The embodiment of the present invention imports the established three-dimensional model of the tank and its anti-sway plate arrangement into the selected CFD simulation software, ensures that the format of the model is correct and can be correctly recognized by the software, inputs the previously set boundary conditions (axial overload, propellant liquid level, angular acceleration field) into the simulation software, selects a suitable solver and algorithm, and after the calculation is completed, analyzes the simulation results to view the propellant's velocity field, pressure field, liquid level fluctuation and other information.

[0064] Step S102, converting the torque of the propellant on the tank to obtain the lateral moment of inertia of the propellant.

[0065] It should be noted that the torque of the propellant on the tank refers to the magnitude of the torsional force around a certain axis generated on the tank due to factors such as the movement and distribution of the propellant. The moment of inertia is a physical quantity that measures the inertia of an object around an axis. For propellants, the lateral moment of inertia reflects the difficulty of its rotation around an axis in a specific direction.

[0066] According to the principles of physics, torque is equal to the moment of inertia multiplied by angular acceleration:

[0067] T=Iy×w; (1)

[0068] Where T represents torque, Iy represents moment of inertia, and w represents angular acceleration;

[0069] When the torque of the propellant on the tank is known, the corresponding angular acceleration needs to be determined. The angular acceleration can be estimated by analyzing the motion and force of the propellant in the simulation. For example, if there is an angular acceleration field due to separation or attitude control, this information can be used to determine the magnitude and direction of the angular acceleration. Once the torque and angular acceleration are determined, the lateral moment of inertia of the propellant can be solved according to the formula that torque equals moment of inertia multiplied by angular acceleration.

[0070] In the embodiment of the present invention, the lateral rotational inertia of the propellant is decomposed into the sum of the lateral rotational inertia of the two propellants (oxidizer and fuel), and the torque of each propellant on the tank obtained by simulation and the angular acceleration at the time of separation or attitude change are substituted into formula (1) to obtain the lateral rotational inertia of each propellant at the corresponding time; the sum of the lateral rotational inertia of each propellant is taken as the lateral rotational inertia of the whole propellant.

[0071] There are usually multiple propellants in a rocket, which act together on the tank and affect the rotation characteristics of the rocket. The embodiment of the present invention adds the lateral rotational inertia of each propellant to obtain the lateral rotational inertia of the entire propellant system, and obtains a more accurate lateral rotational inertia of the propellant, providing reliable data support for the design and performance analysis of the rocket, thereby more comprehensively evaluating the rotation performance of the rocket. Taking the rotational inertia of each propellant into consideration, the influence of the propellant system on the overall rotation performance of the rocket can be comprehensively evaluated, providing guidance for improving the stability and reliability of the rocket.

[0072] In one embodiment, if Figure 5 The following are the CFD simulation results. Figure 5 (a) shows the time-varying trend of the torque in the Z direction. Figure 5 (b) shows the variation trend of the lateral force excitation over time. Figure 6 (a) shows the liquid flow rate and overall shape before being stimulated. Figure 6(b) shows the flow velocity and overall shape after being stimulated. It can be seen that the flow velocity and overall flow velocity of the propellant have changed after being stimulated by the lateral force.

[0073] Step S103, adding the lateral moment of inertia of the propellant and the lateral moment of inertia of the solid part to obtain an evaluation result of the lateral moment of inertia of the liquid rocket upper stage.

[0074] The second sub-stage of the embodiment of the present invention is taken as an example, and its quality characteristics are:

[0075] Ignition time: mass M1, center of mass position X1, lateral moment of inertia Iy1, Iz1;

[0076] At the moment of exhaustion: mass M2, center of mass position X2, lateral moment of inertia Iy2, Iz2.

[0077] According to the calculation formula of rotational inertia:

[0078] Iy1=Iy2+M2×(X1-X2)+Iy f +Iy zlz

[0079] Among them, f ,Iy zlz is the moment of inertia of the propellant and fairing relative to X1, Iy2+M2×(X1-X2) 2 It is the lateral moment of inertia caused by the axis shift.

[0080] Figure 7 The figure shows the ratio of the moment of inertia of the liquid and the solid after the rotation. The moment of inertia of the liquid should be smaller than that of the solid. f ,Iy zlz All are calculated as solid, resulting in inaccurate calculation of the lateral moment of inertia. f By using the lateral rotational inertia of the propellant converted from the above CFD simulation, the final result of the lateral rotational inertia of the upper stage of the liquid rocket as a whole is more accurate.

[0081] The motion state of the upper stage of a liquid rocket during flight is affected by many factors. By adding the lateral rotational inertia generated by different parts, the overall rotational characteristics of the upper stage can be fully and accurately reflected, which helps engineers to have a deeper understanding of the dynamic behavior of the rocket under various working conditions and provide a more reliable basis for design and optimization. For example, when designing attitude control, accurate lateral rotational inertia is a key parameter for calculating the required control torque and determining the control strategy. Only by considering the contribution of the rotational inertia of all major parts can an effective attitude control scheme be formulated.

[0082] The lateral moment of inertia of different parts has different effects on the performance of the rocket. By adding them together, the contribution of each part to the overall performance can be comprehensively evaluated, so as to optimize the design in a targeted manner. For the propellant part, a reasonable design of the tank shape and layout can reduce the sway of the propellant and the impact on the lateral moment of inertia, ensuring the flight stability and accuracy of the rocket. The design of the fairing can minimize its contribution to the lateral moment of inertia while meeting aerodynamic requirements. As for the lateral moment of inertia caused by the axis shift, its impact can be reduced by optimizing the structural layout and connection method. In addition, accurate calculation of the lateral moment of inertia can also help engineers evaluate the performance changes of the rocket in different flight phases and working conditions, formulate response strategies in advance, and improve the reliability and adaptability of the rocket.

[0083] The moment of inertia of the upper stage of a certain type of rocket after the update obtained by the above calculation method is compared with that before the update (both are calculated as solid in the prior art) as shown in the following table. It can be seen that the method provided by the present application can greatly reduce the deviation compared with the prior art:

[0084]

[0085] This embodiment also provides a liquid rocket upper stage lateral moment of inertia assessment system, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0086] The embodiment of the present invention provides a liquid rocket upper stage lateral moment of inertia evaluation system, such as Figure 8 As shown, including:

[0087] The simulation module 801 is used to perform CFD simulation calculation of the propellant tank based on the liquid rocket flight process to obtain the torque value of the propellant on the tank;

[0088] The propellant transverse moment of inertia calculation module 802 is used to convert the torque acting on the tank by the propellant to obtain the propellant's transverse moment of inertia;

[0089] The evaluation result output module 803 is used to add the lateral rotational inertia of the propellant and the lateral rotational inertia of the solid part to obtain the evaluation result of the lateral rotational inertia of the liquid rocket upper stage.

[0090] In some optional implementations, the simulation module includes:

[0091] A three-dimensional model acquisition unit, used to acquire a three-dimensional model of a liquid rocket propellant tank and an arrangement of its anti-sway plates;

[0092] Boundary adjustment setting unit, used to set the boundary conditions of CFD simulation based on the real state of liquid rocket flight;

[0093] A simulation calculation unit is used to perform CFD fluid simulation calculation of the propellant tank based on the three-dimensional model and the boundary conditions.

[0094] In some optional embodiments, the boundary conditions of the CFD simulation include:

[0095] Axial overload, propellant liquid level, and angular acceleration field caused by separation or attitude control similar to those during liquid rocket flight.

[0096] In some optional embodiments, the propellant lateral moment of inertia calculation module 802 includes:

[0097] The corresponding relationship formula acquisition unit is used to obtain the corresponding relationship formula between torque and moment of inertia:

[0098] T = Iy × w;

[0099] Where: T represents torque, Iy represents moment of inertia, and w represents angular acceleration;

[0100] The lateral moment of inertia calculation unit of each propellant substitutes the torque of each propellant on the tank obtained by simulation and the angular acceleration at the time of separation or attitude change into the corresponding relationship formula to obtain the lateral moment of inertia of each propellant at the corresponding time;

[0101] The propellant transverse rotational inertia calculation unit is used to take the sum of the transverse rotational inertia of each propellant as the transverse rotational inertia of the propellant.

[0102] In some optional embodiments, the evaluation result output module 803 adds the lateral moment of inertia of the propellant, the lateral moment of inertia generated by the fairing, and the lateral moment of inertia generated by the axis shift to obtain the lateral moment of inertia of the liquid rocket upper stage.

[0103] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0104] The liquid rocket upper stage lateral rotational inertia evaluation device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above-mentioned functions.

[0105] The embodiment of the present invention also provides a computer device having the above Figure 8 The liquid rocket upper stage lateral moment of inertia evaluation system shown.

[0106] See also Fig. 9 , Fig. 9 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig. 9 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig. 9 A processor 10 is taken as an example.

[0107] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0108] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0109] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0110] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0111] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0112] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0113] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0114] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for evaluating the lateral moment of inertia of a liquid rocket upper stage, characterized in that: include: Based on the liquid rocket flight process, the CFD simulation calculation of the propellant tank is carried out to obtain the torque value of the propellant on the tank; Convert the torque of the propellant on the tank to obtain the lateral moment of inertia of the propellant; The lateral moment of inertia of the propellant is added to the lateral moment of inertia of the solid portion to arrive at an estimate of the lateral moment of inertia of the liquid rocket upper stage.

2. The method according to claim 1, characterized in that CFD simulation of the propellant tank based on the liquid rocket flight process, including: Obtain a three-dimensional model of the liquid rocket propellant tank and its slosh plate arrangement; Set the boundary conditions of CFD simulation based on the actual state of liquid rocket flight; A CFD fluid simulation calculation of the propellant tank is performed based on the three-dimensional model and the boundary conditions.

3. The method according to claim 1, characterized in that The boundary conditions of the CFD simulation include: Axial overload, propellant liquid level, and angular acceleration field caused by separation or attitude control similar to those during liquid rocket flight.

4. The method according to claim 3, characterized in that The step of converting the torque of the propellant on the tank to obtain the lateral moment of inertia of the propellant includes: Get the corresponding formula between torque and moment of inertia: T = Iy × w; Where: T represents torque, Iy represents moment of inertia, and w represents angular acceleration; Substituting the torque of each propellant on the tank obtained by simulation and the angular acceleration at the time of separation or attitude change into the corresponding relationship formula to obtain the lateral moment of inertia of each propellant at the corresponding time; The sum of the lateral rotational inertia of each propellant is taken as the lateral rotational inertia of the propellant.

5. The method according to claim 4, characterized in that The step of adding the lateral moment of inertia of the propellant to the lateral moment of inertia of the solid part to obtain an evaluation result of the lateral moment of inertia of the upper stage of the liquid rocket includes: The lateral moment of inertia of the propellant, the lateral moment of inertia generated by the fairing, and the lateral moment of inertia generated by the axis shift are added together to obtain the lateral moment of inertia of the liquid rocket upper stage.

6. A liquid rocket upper stage lateral moment of inertia assessment system, characterized in that: The system comprises: The simulation module is used to perform CFD simulation calculations on the propellant tank based on the liquid rocket flight process to obtain the torque value of the propellant on the tank; A propellant transverse moment of inertia calculation module, used to convert the torque acting on the tank by the propellant to obtain the propellant's transverse moment of inertia; The evaluation result output module is used to add the lateral rotational inertia of the propellant and the lateral rotational inertia of the solid part to obtain the evaluation result of the lateral rotational inertia of the liquid rocket upper stage.

7. The system according to claim 6, characterized in that The simulation module comprises: A three-dimensional model acquisition unit, used to acquire a three-dimensional model of a liquid rocket propellant tank and an arrangement of its anti-sway plates; Boundary adjustment setting unit, used to set the boundary conditions of CFD simulation based on the real state of liquid rocket flight; A simulation calculation unit is used to perform CFD fluid simulation calculation of the propellant tank based on the three-dimensional model and the boundary conditions.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket according to any one of claims 1 to 5 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket according to any one of claims 1 to 5.

10. A computer program product, characterized in that It comprises computer instructions for causing a computer to execute the method for evaluating the lateral moment of inertia of the upper stage of a liquid rocket according to any one of claims 1 to 5.

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