CN-122021114-A - Method and system for analyzing lightning environment direct effect of fuel tank

CN122021114ACN 122021114 ACN122021114 ACN 122021114ACN-122021114-A

Abstract

The invention belongs to the technical field of fuel tank simulation analysis, and discloses a method and a system for analyzing a lightning environment direct effect of a fuel tank, wherein the method comprises the following steps of establishing a fuel tank simulation model, and setting material properties of the fuel tank simulation model; and performing finite element solution analysis on the fuel tank simulation model with the set material properties to generate a simulation analysis result, and performing comparison verification based on the simulation analysis result and actual lightning stroke test data of the fuel tank. The invention solves the problem that the fuel tank of the aircraft lacks effective simulation analysis means under the lightning environment airworthiness certification clause and regulation requirement, can rapidly cover different lightning stroke scenes, and greatly shortens the analysis period.

Inventors

WANG XINNIAN
CAO XIN
HUI JIE
CHENG PENG
Song ningbo

Assignees

中航西飞民用飞机有限责任公司

Dates

Publication Date: 20260512
Application Date: 20251224

Claims (10)

1. The method for analyzing the lightning environment direct effect of the fuel tank is characterized by comprising the following steps of: Establishing a fuel tank simulation model, and setting material properties of the fuel tank simulation model, wherein the material properties at least comprise anisotropic electric conductivity and anisotropic heat conductivity of the carbon fiber composite material; Carrying out finite element solution analysis on the fuel tank simulation model with the set material properties to generate a simulation analysis result, wherein the simulation analysis result comprises current distribution obtained based on a quasi-static conductive current diffusion model and a fuel tank local temperature rise result obtained based on a temperature ignition source model; and comparing and verifying the simulation analysis result with actual lightning stroke test data of the fuel tank to confirm the effectiveness of the simulation result.
2. The method for analyzing the direct effect of a lightning environment of a fuel tank according to claim 1, further comprising constructing a physical theoretical model before said constructing the fuel tank simulation model, specifically comprising: acquiring anisotropic conductivity parameters and anisotropic heat conductivity coefficient parameters of the carbon fiber composite material; Establishing a quasi-static conductive current diffusion model for solving current distribution based on the conductivity parameters; And establishing a temperature ignition source model for solving a temperature field based on the heat conductivity parameter, the density and the specific heat capacity of the composite material and the Joule heat source obtained by calculation of the current distribution.
3. The method for analyzing the direct effect of lightning environment of fuel tank according to claim 2, wherein the establishing a quasi-static conductive current diffusion model comprises: constructing a quasi-static conduction current diffusion control equation according to the anisotropic conductivity parameter: wherein As a function of the conductivity tensor, As a result of the electrical potential, Is a vector differential operator; and solving the control equation to obtain potential distribution data, and further generating a current density distribution result.
4. The method of analyzing the direct effect of lightning environment of a fuel tank according to claim 2, wherein the modeling the temperature ignition source comprises: Using the current density distribution result as an electrothermal coupling heat source item according to a Joule heat formula Calculating to obtain the body heat source Wherein In order to achieve a current density of the material, Is the conductivity tensor; According to the density of the composite material Specific heat capacity Anisotropic thermal conductivity parameter tensor And the body heat source Establishing an unsteady state heat conduction control equation: wherein In order to be a temperature field, In order to be able to take time, Is a vector differential operator.
5. The method for analyzing the direct effect of lightning environment of fuel tank according to claim 1, wherein the establishing a fuel tank simulation model comprises: selecting a composite material fuel tank section as a simulation analysis object; geometric dimensions are set for the analysis object to generate a fuel tank simulation model, wherein the geometric dimensions comprise the total length, the width and the height of the model and the distance between a current injection point and an outflow point and a fuel tank cover.
6. The method for analyzing the direct effect of a lightning environment of a fuel tank according to claim 2, wherein the setting of the material property of the fuel tank simulation model comprises: and correspondingly inputting the anisotropic heat conductivity coefficient parameter and the electric conductivity parameter of the carbon fiber composite material in the anisotropic material model into the fuel tank simulation model according to the material layering direction to complete material attribute configuration.
7. The method for analyzing the direct effect of a lightning environment of a fuel tank according to claim 1, wherein the finite element solution analysis of the fuel tank simulation model with the set material properties comprises: Adopting tetrahedral grid units to carry out grid division on the fuel tank simulation model to generate a finite element model; Setting current injection points, outflow points and environmental boundary conditions for the finite element model, defining electric connection and conduction paths, and generating a solving model; And carrying out finite element solving on the solving model, and outputting current distribution and a fuel tank local temperature rise result.
8. The method for analyzing the direct effect of the lightning environment of the fuel tank according to claim 1, wherein the comparing and verifying the simulation analysis result with the actual lightning stroke test data of the fuel tank comprises: carrying out a lightning stroke test on the fuel tank test piece, and recording actual lightning stroke test data comprising an actual ablation area; extracting a region with the temperature exceeding the thermal failure threshold value of the material from the local temperature rise result of the simulation analysis result as a simulation ablation region; and calculating the superposition ratio of the actual ablation area and the simulation ablation area, and judging that the simulation analysis result is effective when the superposition ratio is larger than a preset threshold value.
9. A fuel tank lightning environment direct effect analysis system, comprising: The model building and attribute setting module is used for building a fuel tank simulation model, setting material properties of the fuel tank simulation model; the finite element simulation analysis module is used for carrying out finite element solution analysis on the fuel tank simulation model with the set material properties to generate simulation analysis results, wherein the simulation analysis results comprise current distribution and a fuel tank local temperature rise result; and the comparison and verification module is used for carrying out comparison and verification based on the simulation analysis result and actual lightning stroke test data of the fuel tank.
10. An electronic device, the electronic device comprising: at least one processor, and A memory communicatively coupled to the at least one processor; Wherein the memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 8.

Description

Method and system for analyzing lightning environment direct effect of fuel tank Technical Field The invention belongs to the technical field of fuel tank simulation analysis, and particularly relates to a method and a system for analyzing a lightning environment direct effect of a fuel tank. Background In the field of aviation industry, the fuel tank of an aircraft is used as a core component for storing fuel, and the safety of the fuel tank in a lightning environment is directly related to the flight safety of the whole aircraft. When lightning hits the aircraft, strong current and local high temperature can be generated in the fuel tank and related structures, if the current distribution rule and the temperature rise characteristic cannot be accurately mastered, an effective protection design scheme is difficult to formulate, so that the acquisition of physical response data of the fuel tank under the direct effect of lightning becomes a key premise for supporting the lightning protection design and airworthiness evidence of the aircraft fuel tank. At present, the analysis of the direct effect of the lightning environment of an aircraft fuel tank depends on actual lightning stroke tests in the industry. A test platform simulating a lightning environment is built, lightning current is applied to a fuel tank test piece, damage conditions of the test piece, current conduction paths and local temperature changes are observed and recorded, so that lightning protection capacity of the fuel tank is estimated, and part of analysis means introduces a simulation model but adopts isotropic material assumption. The prior art relies on an analysis mode of an actual lightning stroke test, has the problems of high test cost and long period, is difficult to carry out full coverage on different lightning stroke scenes, and cannot provide sufficient early-stage data support for protection design, and on the other hand, the existing simulation model is difficult to effectively guide the forward design of the lightning protection of the fuel tank because the anisotropic property of the carbon fiber composite material is ignored, and accurate current diffusion and temperature rise calculation theoretical support is lacked, so that the deviation between a simulation result and the actual test result is larger. Disclosure of Invention The invention provides a method and a system for analyzing the direct effect of a lightning environment of a fuel tank, which are used for obtaining current distribution and a local temperature rise result through combination of finite element solving analysis and verifying through a test, so that the technical problems that an aircraft fuel tank lacks an effective simulation analysis means to support the forward design of lightning protection and the verification of a navigable evidence collecting test under the requirements of navigable certification clauses and regulations of the lightning environment are solved. The technical scheme of the invention is realized as follows: in a first aspect, the invention provides a method for analyzing the lightning environment direct effect of a fuel tank, comprising the following steps: Establishing a fuel tank simulation model, and setting material properties of the fuel tank simulation model, wherein the material properties at least comprise anisotropic electric conductivity and anisotropic heat conductivity of the carbon fiber composite material; Carrying out finite element solution analysis on the fuel tank simulation model with the set material properties to generate a simulation analysis result, wherein the simulation analysis result comprises current distribution obtained based on a quasi-static conductive current diffusion model and a fuel tank local temperature rise result obtained based on a temperature ignition source model; and comparing and verifying the simulation analysis result with actual lightning stroke test data of the fuel tank to confirm the effectiveness of the simulation result. The method for constructing the fuel tank simulation model comprises the following steps of constructing a physical theoretical model before constructing the fuel tank simulation model, wherein the method comprises the following steps of: acquiring anisotropic conductivity parameters and anisotropic heat conductivity coefficient parameters of the carbon fiber composite material; Establishing a quasi-static conductive current diffusion model for solving current distribution based on the conductivity parameters; And establishing a temperature ignition source model for solving a temperature field based on the heat conductivity parameter, the density and the specific heat capacity of the composite material and the Joule heat source obtained by calculation of the current distribution. The method for establishing the quasi-static conductive current diffusion model comprises the following steps of: constructing a quasi-static conduction current diffusion control eq