An aircraft brake wheel temperature field simulation method and system

Abstract

The application discloses a kind of simulation method and system of aircraft brake wheel temperature field, it is related to temperature field simulation field, the method includes determining the three-dimensional grid model of solid region and setting range fluid region of brake wheel;Determine the material of each fluid region, the material parameter of fluid region and solid region;Determine the flow field boundary of fluid region to fluid region and the fluid-structure coupling interface between solid region and fluid region;Determine brake disc brake power fitting function and non-brake disc loss power function;And according to brake disc brake power fitting function and non-brake disc loss power function determine heat source load;According to three-dimensional grid model, the material of each fluid region, the material parameter of fluid region, the material parameter of solid region, flow field boundary, fluid-structure coupling interface and heat source load, utilize the fluid calculation module of ANSYS system to simulate aircraft brake wheel temperature field.The simulation precision of brake wheel temperature field can be improved by the application.

Description

Technical Field

[0001] This invention relates to the field of temperature field simulation, and in particular to a method and system for simulating the temperature field of an aircraft brake wheel. Background Technology

[0002] Brake wheels equipped with brake discs bring an aircraft to a stop on the runway, during which the aircraft's kinetic energy is converted into heat and released. Aircraft braking kinetic energy can be categorized into two types based on its conversion path: one is non-disc-induced energy loss, which is lost through the rolling and sliding of the tires on the ground; the other is disc-induced braking energy, the converted heat of which is absorbed by heat sinks. After the aircraft stops, this heat continuously transfers from high-temperature to low-temperature locations, which is the main factor causing the temperature rise of the brake wheels and surrounding environment. Due to the high speed and large kinetic energy of aircraft during taxiing, excessively high temperatures after braking can cause tire material aging and even tire blowouts. Therefore, accurate simulation and prediction of the temperature field of the brake wheels and surrounding air are key technologies and economic methods for ensuring the safe and stable operation of aircraft and for developing temperature control measures.

[0003] CFD is a commonly used numerical simulation method in engineering for predicting fluid-structure interaction temperature fields. The accuracy of temperature field calculation using this method usually depends on several factors, such as the selection of material parameters, the setting of boundaries and interfaces, and the definition of heat source load conditions. Braking power of the brake disc, as a major factor in the heat source load conditions, plays a crucial role in the accurate simulation of the temperature field of the brake wheel.

[0004] Currently, in temperature field calculations, the brake disc braking energy is obtained by first subtracting non-disc loss energy from the total braking energy based on empirical values. The brake disc braking power is typically expressed as an equivalent average power. While this empirical equivalence meets calculation requirements within a certain accuracy range, it becomes insufficient when studying specific operating conditions. For example, the brake disc friction coefficient, which varies with temperature, causes the brake disc braking power to change over time. Therefore, it is necessary to propose a method that can adequately describe the change in brake disc braking power over time, thereby further improving the accuracy of temperature field simulations. Summary of the Invention

[0005] The purpose of this invention is to provide a simulation method and system for the temperature field of aircraft brake wheels, which can improve the simulation accuracy of the temperature field of brake wheels.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A simulation method for the temperature field of an aircraft brake wheel includes:

[0008] A three-dimensional mesh model is created to define the solid region of the brake wheel and the fluid region within a specified range.

[0009] Determine the materials for each fluid region, the material parameters for the fluid region, and the material parameters for the solid region; the material parameters include: density, specific heat, and thermal conductivity; and determine the material parameters and the material variations of the fluid region with temperature.

[0010] Determine the flow field boundaries between fluid regions and the fluid-structure interaction interface between the solid and fluid regions;

[0011] Determine the brake disc braking power fitting function and the non-brake disc loss power function; and determine the heat source load based on the brake disc braking power fitting function and the non-brake disc loss power function.

[0012] Based on the three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load, the temperature field of the aircraft brake wheel is simulated using the fluid calculation module of the ANSYS system.

[0013] Optionally, the three-dimensional mesh model for determining the solid region and the fluid region within a set range of the brake wheel specifically includes:

[0014] A geometric model was established based on the temperature field characteristics of the aircraft brake wheels and ground test conditions; the ground test conditions included: ambient temperature, wind speed in the wheel heading direction, wheel clearance from the ground, and distance between the wheel and the flywheel.

[0015] Determine the geometric model based on the geometric model.

[0016] Optionally, the brake disc braking power fitting function is:

[0017]

[0018] Where W(t) is the brake disc braking power fitting function, M(t) is the fitting polynomial function obtained from the measured braking torque curve, v(t) is the fitting polynomial function obtained from the measured braking speed change curve, Rgd is the tire rolling radius, T is the braking process time, and t is the current time.

[0019] Optionally, the power loss function of the non-brake disc is:

[0020]

[0021] Where re represents the percentage of braking energy from the brake disc. E represents the total braking energy of a single aircraft wheel. This refers to the braking energy of the brake disc.

[0022] Optionally, the fluid computation module includes: a turbulence model, an energy equation model, and a radiation model.

[0023] Optionally, the simulation results include: temperature variation curves at the measuring points over time and temperature field contour maps of the brake wheel.

[0024] A simulation system for the temperature field of an aircraft brake wheel, comprising:

[0025] The 3D mesh model determination module is used to determine the 3D mesh model of the solid region and the fluid region within a set range of the brake wheel;

[0026] The parameter determination module is used to determine the material of each fluid region, the material parameters of the fluid region, and the material parameters of the solid region; the material parameters include: density, specific heat, and thermal conductivity; the material parameters and the material of the fluid region change with temperature;

[0027] The interface determination module is used to determine the flow field boundary between fluid regions and the fluid-structure interaction interface between the solid region and the fluid region.

[0028] The heat source load determination module is used to determine the brake disc braking power fitting function and the non-brake disc loss power function; and to determine the heat source load based on the brake disc braking power fitting function and the non-brake disc loss power function.

[0029] The simulation module is used to simulate the temperature field of aircraft brake wheels using the fluid calculation module of the ANSYS system, based on the three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load.

[0030] A simulation system for the temperature field of an aircraft brake wheel includes: at least one processor, at least one memory, and computer program instructions stored in the memory. When the computer program instructions are executed by the processor, the simulation method for the temperature field of an aircraft brake wheel is implemented.

[0031] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0032] This invention provides a simulation method and system for the temperature field of aircraft brake wheels. It determines the brake disc braking power fitting function and the non-brake disc power loss function; then, based on these functions, it determines the heat source load; and finally, using the fluid calculation module of the ANSYS system, it simulates the temperature field of the aircraft brake wheels based on a three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load. By proposing a time-varying brake power fitting function through the heat source load, and applying the heat source load in a manner close to actual operating conditions, the accuracy of the simulation results is ensured. This overcomes the shortcomings of traditional methods that cannot accurately consider the time-varying brake disc braking power, improving the accuracy of the brake wheel temperature field simulation calculation and providing conditions for further research on the temperature field distribution and heat management of brake wheels. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a simulation method for the temperature field of an aircraft brake wheel provided by the present invention.

[0035] Figure 2 This is a schematic diagram of the geometric model;

[0036] Figure 3 This is a schematic diagram of a 3D mesh model;

[0037] Figure 4 This is a schematic diagram of another 3D mesh model;

[0038] Figure 5 A schematic diagram showing the measured curve of braking torque and the calculated value of the fitted polynomial function;

[0039] Figure 6 A schematic diagram showing the measured braking speed curve and the calculated value of the fitted polynomial function;

[0040] Figure 7 A schematic diagram showing the calculated value of the fitting function W(t) for the brake disc braking power as a function of time.

[0041] Figure 8 A schematic diagram of the friction interface between brake discs;

[0042] Figure 9 This is a schematic diagram of the grid at the interface between the tire and the ground.

[0043] Figure 10 This is a schematic diagram of the temperature change curve at a measuring point on the brake disc.

[0044] Figure 11 A schematic diagram of the temperature change curve at a measuring point on the wheel hub;

[0045] Figure 12 The temperature field contour map of the brake wheel (at 8s);

[0046] Figure 13 This is a temperature field contour map of the brake wheel (at 312 s). Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] The purpose of this invention is to provide a simulation method and system for the temperature field of aircraft brake wheels. By defining the heat source load through a braking power fitting function that varies with time, the simulation accuracy of the brake wheel temperature field can be further improved, realizing the study of the brake wheel temperature field under the condition of braking power loading that varies with time.

[0049] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Figure 1 This is a schematic diagram of a simulation method for the temperature field of an aircraft brake wheel provided by the present invention; as shown. Figure 1 As shown, the simulation method for the temperature field of an aircraft brake wheel provided by the present invention includes:

[0051] S101, Determine the three-dimensional mesh model of the solid region and the fluid region within the set range of the brake wheel;

[0052] S101 establishes a geometric model based on the temperature field characteristics of the aircraft brake wheel and ground test conditions. These ground test conditions include: ambient temperature, wind speed along the wheel's heading, wheel clearance from the ground, and distance between the wheel and the flywheel. The temperature field characteristics of the aircraft brake wheel refer to the temperature variation with space and time within a region (occurring in both solid and fluid heat transfer regions). The solid heat transfer region is determined by the shape, size, and connection method of the various components of the brake wheel (tires, hubs, brake discs, etc.). The fluid heat transfer region refers to the air surrounding the solid.

[0053] Determine the geometric model according to the geometric model, such as Figure 2 shown.

[0054] The specific implementation is to import the geometric model into the mesh generation module of the ANSYS system, and create a three-dimensional mesh model of the solid region of the brake wheel and the fluid region around it, such as Figure 3 and Figure 4 shown.

[0055] S102, determine the materials of each fluid region, the material parameters of the fluid region and the material parameters of the solid region; the material parameters include: density, specific heat and thermal conductivity; the material parameters and the materials of the fluid region change with temperature;

[0056] As a specific embodiment, the materials of fluid regions such as the surrounding air and the gas inside the tire are set as the ideal gas model, and the air density changes with temperature. Set the direction of the gravitational acceleration to be vertically downward to simulate the upward floating of hot air during natural convection heat dissipation.

[0057] S103, determine the flow field boundary between fluid regions and the fluid-structure interaction interface between the solid region and the fluid region;

[0058] Set the lower boundary surface of the flow field boundary as the velocity inlet, set the flow velocity to zero during natural cooling, and set other flow field boundary surfaces as the pressure outlet; set the fluid-structure interaction wall surface on the fluid-structure interaction interface.

[0059] S104, determine the fitting function of the braking power of the brake disc and the loss power function of the non-brake disc; and determine the heat source load according to the fitting function of the braking power of the brake disc and the loss power function of the non-brake disc;

[0060] The fitting function of the braking power of the brake disc is:

[0061]

[0062] where, W(t) is the fitting function of the braking power of the brake disc, M(t) is the fitting polynomial function obtained from the measured curve of the braking torque, v(t) is the fitting polynomial function obtained from the measured curve of the change of the braking speed, Rgd is the tire rolling radius, T is the braking process time, and t is the current time.

[0063] Due to the influence of the friction coefficient and the change of the braking pressure under specific working conditions, the braking torque and the braking speed show a certain degree of non-linear change. The fitting polynomial functions of M(t) and v(t) when t < T under the normal braking kinetic energy condition of a certain brake wheel are:

[0064] M(t) = -0.12421t 6 + 2.63934t 5-23.37206t 4 +105.63839t 3 -218.51322t 2 +570.57542t + 4867.82605

[0065] v(t) = -0.00385228t 3 -0.0487698t 2 -1.6141169t + 19.4910122

[0066] The calculated value and the original measured curve are shown in Figure 5 and Figure 6 . Then, when t < T, the fitting function W(t) of the braking disc braking power varying with time is:

[0067] W(t) = 0.0016t 9 -0.0137t 8 +0.5394t 7 -19.8279t 6 +282.8616t 5 -2058.7t 4 +7883.8t 3 -18058t 2 +10880t + 316260, and the corresponding calculated value is shown in Figure 7 .

[0068] The non-braking disc loss power function is:

[0069]

[0070] where re is the proportion of the braking disc braking energy, E is the total braking energy of a single wheel of the aircraft, is the braking disc braking energy.

[0071] It is known that the total braking energy of a single wheel of this aircraft under the normal braking kinetic energy condition is E = 2.1×10 6 J, the braking process time T = 8.454 s, then the braking disc braking energy is Ee = 1.9065×10 6 J, and the proportion re of the braking disc braking energy is 90.79%. Then, when t < T, the non-braking disc loss power function is W f (t) = 0.1015 * W(t).

[0072] The specific implementation is: Create a user-defined function program DEFINE_PROFILE(heat_wt, thread, ti) according to the power function W(t), at the friction interface grid between the braking discs (see Figure 8Apply heat generation power udf_heat_wt to the surface; based on the power function W f (t) Create a user-defined function program DEFINE_PROFILE(heat_wft,thread,ti) on the mesh of the tire-ground interface (see...). Figure 9 Apply heat generation power udf_heat_wft to )

[0073] S105. Based on the 3D mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundaries, the fluid-structure interaction interface, and the heat source load, the temperature field of the aircraft brake wheel was simulated using the fluid calculation module of the ANSYS system. The simulation results include: the temperature variation curve of the measuring point over time and the temperature field contour map of the brake wheel.

[0074] The 3D mesh model was imported into the fluid calculation module of the ANSYS system. The fluid calculation module includes general calculation models in the CFD method. In order to simulate the heat transfer modes such as heat conduction, heat convection and heat radiation between the brake wheel and the surrounding fluid, the turbulence model, energy equation model and radiation model were selected to participate in the fluid calculation module.

[0075] The temperature field of the brake wheel was calculated using the fluid dynamics module, and the temperature variation curves over time at the measuring points were extracted using the ` / solve / monitors` command. Figure 10 and Figure 11 After solving, the temperature field contour map of the brake wheel is output using the contours tool, see [link / reference]. Figure 12 and Figure 13 .

[0076] This invention also provides an embodiment, specifically a simulation system for the temperature field of an aircraft brake wheel, comprising:

[0077] The 3D mesh model determination module is used to determine the 3D mesh model of the solid region and the fluid region within a set range of the brake wheel;

[0078] The parameter determination module is used to determine the material of each fluid region, the material parameters of the fluid region, and the material parameters of the solid region; the material parameters include: density, specific heat, and thermal conductivity; the material parameters and the material of the fluid region change with temperature;

[0079] The interface determination module is used to determine the flow field boundary between fluid regions and the fluid-structure interaction interface between the solid region and the fluid region.

[0080] The heat source load determination module is used to determine the brake disc braking power fitting function and the non-brake disc loss power function; and to determine the heat source load based on the brake disc braking power fitting function and the non-brake disc loss power function.

[0081] The simulation module is used to simulate the temperature field of aircraft brake wheels using the fluid calculation module of the ANSYS system, based on the three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load.

[0082] In order to implement the method corresponding to Embodiment 1 above and achieve the corresponding functions and technical effects, the present invention also provides a simulation system for the temperature field of an aircraft brake wheel, comprising: at least one processor, at least one memory, and computer program instructions stored in the memory, wherein when the computer program instructions are executed by the processor, the simulation method for the temperature field of an aircraft brake wheel is implemented.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0084] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A simulation method for the temperature field of an aircraft brake wheel, characterized in that, include: A three-dimensional mesh model is created to define the solid region of the brake wheel and the fluid region within a specified range. Determine the materials for each fluid region, the material parameters for the fluid region, and the material parameters for the solid region; The material parameters include: density, specific heat, and thermal conductivity; the material parameters and the material variation in the fluid region with temperature; Determine the flow field boundaries between fluid regions and the fluid-structure interaction interface between the solid and fluid regions; Determine the brake disc braking power fitting function and the non-brake disc loss power function; and determine the heat source load based on the brake disc braking power fitting function and the non-brake disc loss power function. Based on the three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load, the temperature field of the aircraft brake wheel is simulated using the fluid calculation module of the ANSYS system.

2. The simulation method for the temperature field of an aircraft brake wheel according to claim 1, characterized in that, The three-dimensional mesh model that determines the solid region and the fluid region within a set range of the brake wheel specifically includes: A geometric model was established based on the temperature field characteristics of the aircraft brake wheels and ground test conditions; the ground test conditions included: ambient temperature, wind speed in the wheel heading direction, wheel clearance from the ground, and distance between the wheel and the flywheel. The three-dimensional mesh model is determined based on the geometric model.

3. The simulation method for the temperature field of an aircraft brake wheel according to claim 1, characterized in that, The brake disc braking power fitting function is: ； in, This is the fitting function for the brake disc braking power. It is a fitted polynomial function obtained from the measured curve of braking torque. It is a fitted polynomial function obtained from the measured curve of braking speed change. T is the tire's rolling radius, T is the braking time, and t is the current moment.

4. The simulation method for the temperature field of an aircraft brake wheel according to claim 3, characterized in that, The power loss function of the non-braking disc is: ； in, This represents the percentage of braking energy from the brake disc. E represents the total braking energy of a single aircraft wheel. This refers to the braking energy of the brake disc.

5. The simulation method for the temperature field of an aircraft brake wheel according to claim 1, characterized in that, The fluid computation module includes: turbulence model, energy equation model, and radiation model.

6. The simulation method for the temperature field of an aircraft brake wheel according to claim 1, characterized in that, The simulation results include: temperature variation curves at the measuring points over time and temperature field contour maps of the brake wheel.

7. A simulation system for the temperature field of an aircraft brake wheel, characterized in that, include: The 3D mesh model determination module is used to determine the 3D mesh model of the solid region and the fluid region within a set range of the brake wheel; The parameter determination module is used to determine the material of each fluid region, the material parameters of the fluid region, and the material parameters of the solid region. The material parameters include: density, specific heat, and thermal conductivity; the material parameters and the material variation in the fluid region with temperature; The interface determination module is used to determine the flow field boundary between fluid regions and the fluid-structure interaction interface between the solid region and the fluid region. The heat source load determination module is used to determine the brake disc braking power fitting function and the non-brake disc loss power function; and to determine the heat source load based on the brake disc braking power fitting function and the non-brake disc loss power function. The simulation module is used to simulate the temperature field of aircraft brake wheels using the fluid calculation module of the ANSYS system, based on the three-dimensional mesh model, the materials of each fluid region, the material parameters of the fluid region, the material parameters of the solid region, the flow field boundary, the fluid-structure interaction interface, and the heat source load.

8. A simulation system for the temperature field of an aircraft brake wheel, characterized in that, include: The method comprises at least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement a simulation method for the temperature field of an aircraft brake wheel as described in any one of claims 1-6.

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