CN104461677B - A kind of virtual thermal test method based on CFD and FEM technologies - Google Patents
A kind of virtual thermal test method based on CFD and FEM technologies Download PDFInfo
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Abstract
A kind of virtual thermal test method based on CFD and FEM technologies, arc tunnel dummy model is set up using Fluid Mechanics Computation method, realizes trystate thermal environment accurate simulation and amendment；Testpieces model is set up using finite element method, is set up including typical model parameter, testpieces model boundary is accurately set up, and determines that test model being capable of accurate simulation actual tests part；Two kinds of model combine analogs are realized using fluid structurecoupling technology, test model amendment and solidification are completed using Modifying model and model verification technique.All kinds of heat structure virtual tests are completed using this method, can significantly shorten the test period, testing expenses are reduced.
Description
Technical field
The present invention relates to a kind of virtual thermal test method based on CFD and FEM technologies, belong to hypersonic Aerodynamic Heating ring
Border, heat protection design and heat structure wind-tunnel technique association area.
Background technology
The features such as hypersonic aircraft thermal environment has " enthalpy height, time length, total heat carry big ", whole aircraft heat is anti-
Protecting system organization plan is complicated, ensures system integrity while meeting anti-heat-proof quality, therefore thermal protection system is anti-heat-insulated
Experiment examination is significant.Because the hot certification test of thermal protection structure has big experiment difficulty, test period length and experiment funds
High the characteristics of, in order to ensure project Development Schedule, hypersonic thermal protection system design, evaluation level are further improved, having must
Thermal protection experimental technique and numerical simulation technology are combined, develops a kind of thermal protection structure virtual experiment technology.
Carry out pneumatic thermal environment numerical value and experimental study first in thermal protection system design, on the basis of clear and definite environmental condition
Upper development thermal protection system conceptual design, on the basis of conceptual design, carries out the hot certification test of type testing part arc tunnel.
Not yet find the heat structure virtual experiment technology related data for hypersonic thermal protection system both at home and abroad at present.But heat is examined
Nuclear test implementation faces huge difficulty, specifically includes following three aspects reason.One is that experiment difficulty is big：It is limited to wind-tunnel ability, it is right
Tend not to realize performance assessment criteria with coarse scale structures, and there is great risk in experiment；Two be that the test period is long：Tissue is completed
Once hot certification test generally requires the test period of more than 1 year；Three be that testing expenses are high：Due to hypersonic aircraft heat
The characteristics of guard assembly, its hot certification test often reaches the domestic test level limit, consumes huge, therefore testing expenses are very
It is high.
Although Aerodynamic Heating and structure thermal response have become a critically important research direction.But, at present very
In many research work, both is separated.In fact, the two problems are not isolated, but a unification is continuous
Process.With flow field at object plane by hot-fluid energy exchange occurs for structure, and hot-fluid computational accuracy can also directly affect Calculation of Heat Transfer
As a result, this calculates for the coupling of flow field and structural thermal and is particularly important.In traditional Calculation of Heat Transfer, often use
Flow field is first calculated, providing surface heat flow by Flow Field Calculation is distributed, and the revised hot-fluid of carry out hot wall is then loaded into solid table
Face, then calculate the Temperature Distribution in solid.But adopt this method when calculating the Temperature Distribution in structure, often different journeys
The Temperature Distribution of structure is over-evaluated on degree ground, therefore generates the computational methods of flow field/structure Coupling heat transfer.
The content of the invention
The technology of the present invention solves problem：Overcome the deficiencies in the prior art there is provided a kind of based on CFD＆FEM technologies
Thermal protection structure virtual test method.Solve current thermal protection structure experiment examination cycle length, costly, experimental technique difficulty
Greatly, the low problem of maturity.
The present invention technical solution be：
A kind of virtual thermal test method based on CFD and FEM technologies, step is as follows：
(1) thermal environment to hypersonic aircraft is calculated, and is specially：Hypersonic aircraft outer surface is carried out
Region division, is divided into Vehicle nose's spherical area and aircraft fuselage plane domain, for aircraft spherical area, thermal environment
Calculate and carried out by formula：
In formula：Q is heat flow density, ω=0.52, ρswFor the density of aircraft wall gas；μswFor aircraft wall gas
The viscosity of body, Pr=0.71, Le=1.0-2.0, ρsFor the gas density in stationary point, μsFor the viscosity of the gas in stationary point,
hDFor dissociation enthalpy, hsFor stagnation enthalpy, hswFor wall enthalpy；For the velocity gradient at stationary point, obtained from the Newton's formula of amendment
, calculation formula is：RoFor radius of curvature, psFor stagnation pressure, p∞For far field force；
For aircraft fuselage plane domain, thermal environment is calculated to be carried out by equation below：At aircraft surface flow field
When laminar condition,When aircraft surface flow field is in turbulence state,In formula：For the Reynolds number estimated under reference conditions, ρ is
Far field density, UeFor reference velocity, x is reference length, gc=32.174, μ are to refer to viscosity, τm=1, hrTo recover enthalpy；
(2) boxed area is chosen on the thermal protection shield of hypersonic aircraft surface as testpieces, the testpieces is existed
Geometric Modeling is carried out in D modeling tool；
(3) determine to carry out the wind-tunnel that virtual heat test is used, the wind-tunnel needs to meet：A, wind tunnel nozzle diameter are more than experiment
1.2 times of part envelope size, b, the maximum of wind tunnel nozzle outlet hot-fluid are more than aircraft thermal environment calculating in step (1) and obtained
1.2 times of hot-fluid；
When the testpieces chosen position is Vehicle nose, the maximum of wind tunnel nozzle outlet hot-fluid is more than step (1)
1.2 times of middle aircraft spherical area thermal environment hot-fluid；When the testpieces chosen position is aircraft fuselage plane domain, wind
The maximum of hole nozzle exit hot-fluid is more than 1.2 times of aircraft fuselage plane domain thermal environment hot-fluid in step (1)；
(4) virtual arc tunnel CFD model is set up in computational fluid dynamics instrument, under Cartesian coordinates, is led to
Cross the compressible Reynolds average NS side of three-dimensional non-steady that the virtual arc tunnel CFD model solves thermal chemical reaction ideal gas
Journey, the equation is：
WhereinFor conservation variable, t is the time,For x, y, the nothing on tri- directions of z glues the flux of vector,For x, y, the sticky momentum flow vector on tri- directions of z obtains wall heat flux density q；
(5) according to the geometrical model and material of testpieces, virtual test part FEM heat transfers are set up in finite element analysis instrument
Model, is calculated by following heat transfer equation, obtains the wall surface temperature T of the testpiecessw；
Heat transfer equation is：
Wherein, ρ is structure effective density, and c is effective specific heat, and T is temperature, kx,ky,kzFor x, y, having on tri- directions of z
Imitate the coefficient of heat conduction；
(6) formula is passed throughBy wall surface temperature TswEnter row interpolation, be used as step
(4) wall heat flux density q boundary condition, wherein T are solved ini,j,1The temperature obtained for fluid boundary (i, j, 1) unit interpolation,
Ti+1,j,1,Ti1,j,1,Ti,j+1,1,Ti,j-1,1Respectively construction unit projects obtained temperature on element of fluid；
Pass through formulaWall heat flux density q is entered into row interpolation, as seeking wall surface temperature T in step (5)sw
Boundary condition, wherein, qn,snHeat flow density and cellar area on respectively element of fluid n,siRespectively construction unit
Heat flow density and cellar area on i；
Using the structural thermal characteristic time as coupling calculate time step, iterative cycles iterative step (4) and
The virtual heat test fluid structure interaction mode that step (5) is just obtained；
(7) according to the virtual heat test fluid structure interaction mode obtained in step (6), virtual heat test is carried out, i.e. wind-tunnel blows
Wind is tested, and obtains the time and space distribution and the time and space distribution of stress of time and space distribution, the displacement of testpieces temperature；
(8) what the result and the virtual blowing test of progress that actual experimental part is blowed to experiment in true wind-tunnel were obtained
As a result it is compared, if comparison result is within preset range, then it is assumed that the virtual heat test fluid structure interaction mode is accurate；
If comparison result is outside preset range, then it is assumed that the virtual heat test fluid structure interaction mode is inaccurate, to described virtual
Heat test fluid structure interaction mode is modified, return to step (4).
The computational fluid dynamics instrument is CFD++ or FASTRAN.
The finite element analysis instrument is ANSYS or ABAQUS.
Described that virtual heat test fluid structure interaction mode is modified, specific method is：
(4.1) to CFD model amendment, fluid grid yardstick is adjusted；
(4.2) to testpieces FEM heat transfer model amendments, structured grid yardstick is adjusted；
(4.3) formula is usedThe heat flow density q on fluid and structure interface face is corrected, to ensure in stream
Body and the structure interface face conservation of energy.
Compared with the prior art, the invention has the advantages that：
(1) present invention proposes a kind of new virtual arc tunnel blowing test method, with reference to CFD technologies and FEM methods, leads to
The Coupled Heat Transfer that fluid-solid coupling technique realizes fluid model and structural model is crossed, virtual thermal test fluid-solid coupling is set up
Matched moulds type, to simulate the state of true arc tunnel blowing test, this method reduces true arc tunnel test failure
Risk, and shorten the model lead time, project research fund is greatly reduced；
(2) COUNTABLY VALUED simulation thermal chemical reaction ideal gas of the present invention, can according to circumstances use 7 components and 11 component moulds
Type, more realistically simulates arc tunnel blowing test situation；
(3) present invention establishes the wall surface temperature between element of fluid and construction unit and wall heat flux transmission interpolation side
Method, can make to couple calculating with carrying out fluid-solid under structured grid mismatch case in fluid grid, substantially increase structure biography
The efficiency of heat, calculates fluid-solid Coupled Heat Transfer from theory and has pushed engineer applied to；
Brief description of the drawings
Fig. 1 is flow chart of the present invention；
Fig. 2 is fluid grid and structured grid schematic diagram
Fig. 3 is typical heat guard assembly result of the test and virtual test Comparative result curve map, wherein, Fig. 3 (a) is virtual
Blowing test result, Fig. 3 (b) is true arc tunnel result of the test.
Embodiment
The embodiment to the present invention is further described in detail below in conjunction with the accompanying drawings.
Thermal protection structure virtual test method can effectively solve the problem that actual tests difficulty is big, cycle length, costly difficulty.
During proposition method of the present invention foundation, virtual wind tunnel model is set up first with CFD technologies, is secondly built using FEM methods
Vertical virtual test part model, reuses the coupling that fluid structurecoupling technology realizes two models, and test examination using thermal protection
As a result model is modified, forms various hot virtual test databases.
As shown in figure 1, the invention provides a kind of virtual thermal test method based on CFD and FEM technologies, step is as follows：
(1) thermal environment to hypersonic aircraft is calculated, and is specially：Hypersonic aircraft outer surface is carried out
Region division, is divided into Vehicle nose's spherical area and aircraft fuselage plane domain, for aircraft spherical area, thermal environment
Calculate and carried out by formula：
In formula：Q is heat flow density, ω=0.52, ρswFor the density of aircraft wall gas；μswFor aircraft wall gas
The viscosity of body, Pr=0.71, Le=1.0-2.0, ρsFor the gas density in stationary point, μsFor the viscosity of the gas in stationary point,
hDFor dissociation enthalpy, hsFor stagnation enthalpy, hswFor wall enthalpy；For the velocity gradient at stationary point, obtained from the Newton's formula of amendment
, calculation formula is：RoFor radius of curvature, psFor stagnation pressure, p∞For far field force；
For aircraft fuselage plane domain, thermal environment is calculated to be carried out by equation below：At aircraft surface flow field
When laminar condition,When aircraft surface flow field is in turbulence state,In formula：For the Reynolds number estimated under reference conditions, ρ*
For far field density, UeFor reference velocity, x is reference length, gc=32.174, μ are to refer to viscosity, τm=1, hrTo recover
Enthalpy；
(2) boxed area is chosen on the thermal protection shield of hypersonic aircraft surface as testpieces, the testpieces is existed
Geometric Modeling is carried out in D modeling tool；
(3) determined to carry out operating condition of test, the test bar of virtual heat test according to the wall heat flux density obtained in step (1)
Part and the wind-tunnel used, the wind-tunnel need to meet：A, wind tunnel nozzle diameter are more than 1.2 times of testpieces envelope size, b, wind-tunnel
The maximum of nozzle exit hot-fluid is more than 1.2 times that aircraft thermal environment calculating in step (1) obtains hot-fluid；
When the testpieces chosen position is Vehicle nose, the maximum of wind tunnel nozzle outlet hot-fluid is more than step (1)
1.2 times of middle aircraft spherical area thermal environment hot-fluid；When the testpieces chosen position is aircraft fuselage plane domain, wind
The maximum of hole nozzle exit hot-fluid is more than 1.2 times of aircraft fuselage plane domain thermal environment hot-fluid in step (1)；
(4) fluid grid is divided in computational fluid dynamics instrument, virtual arc tunnel CFD model is set up, in flute card
Under youngster's coordinate system, the three-dimensional non-steady for solving thermal chemical reaction ideal gas by the virtual arc tunnel CFD model can be pressed
Contracting Reynold's average NS equation, the equation is：
Wherein,
Its viscous stress is respectively：
For ideal gas, stateful equation p=ρ RT, h=CpT
The gross energy of unit-gas is
For isotropic fluid, thermal conductivity factor
In formulaFor conservation variable, t is the time,For x, y, the nothing on tri- directions of z glues the flux of vector,For x, y, the sticky momentum flow vector on tri- directions of z, u, v, w is x, y, the speed on tri- directions of z, CpIt is fixed
Pressure ratio thermal capacitance, specific heat ratio γ=1.4, R takes 287；
Above-mentioned partial differential equations are solved by the following method, obtain wall heat flux densityN is wall
Normal direction；
The gas model that a is used
In arc tunnel process of the test, because gas temperature is high, chemically react, therefore using heat in equation
Chemically react ideal gas model.Multicomponent mixed gas is a variety of hot ideal gases compositions, the total interior energy of unit mass gas by
Translation energy, rotation energy, vibrational energy and electronic excitation energy multiple kinds of energy pattern.Using dual temperature model hypothesis, each component i energy
Pattern is as follows：
Mixed gas interior energy value and component interior energy：
Mixed gas enthalpy h and component enthalpy hi：
Wherein, YiFor each component i percentages, cp,iFor i component specific heat at constant pressures,For chemical enthalpy (enthalpy of formation).
This research primarily focuses on the reaction between constituent of air under hot conditions, for only considering the pure of two kinds of elements of N, O
Air, is respectively adopted 7 components and 11 compositional models, using finite-rate reaction model.
B method of value solving
Spatial spreading
Spatial spreading form has considerable influence for the computational accuracy and stability in flow field, and present study is used through a large amount of
The Roe of engineering practice detection FDS forms carry out spatial spreading.According to the building method of Roe forms, have：
DefinitionThen
Represent to QL,QRUsing Roe averaging methods calculate obtained conservation variable, i.e.,:
Definition:Then have
According to Jacobian matrixThree different characteristic values, can be three groups of vectorial sums by artificial dissipation's term separation,
I.e.：
Wherein：
Δ ()=()R-()L
Roe FDS forms are a kind of approximate Riemann's method for solving, and it has natural high-resolution to discontinuous problem, therefore
It is very suitable for solving the class shearing motion of viscous fluid in boundary layer.But because Roe forms are substantially that one kind will be non-linear
Problem is converted into the approximate fits to linear Riemannian problem, therefore it is difficult the institute that nonlinear problem completely and is exactly depicted
There is feature, the physical description of mistake can be even produced sometimes, such as when crossing velocity of sound expansion, Roe forms can calculate expansion and swash
Ripple.The reason for producing this non-physical phenomenon is, due to lacking the limitation of entropy condition, in the case where characteristic value goes to zero,
Roe forms are difficult to the direction of propagation for correctly judging ripple.For this reason, it may be necessary to be artificially induced entropy amendment, the expansion of non-physical is swashed
Ripple dissipates to expand sector, is allowed to meet entropy condition.Here anisotropic Muller types entropy modified formulation is used：
Wherein σnFor normal direction spectral radius, στ1,στ2For tangential spectral radius,0.1-0.4 is typically taken as empirical.
Time discrete
For limited bulk semi-discrete scheme, handled without viscous flux using implied format, sticky flux uses explicit processing,
It can then be written as：
Wherein Ω is unit volume, Jacobian matrix of the definition without viscous flux：
Then have
Equation left end is substituted into, is arranged
Wherein
According to principle windward, it will pressed just without viscous flux Jacobian matrixes, negative feature value enters line splitting,
(AΔQ)i+1,J,K=(A+ΔQ)I,J,K+(A-ΔQ)I+1,J,K
(AΔQ)i,J,K=(A+ΔQ)I-1,J,K+(A-ΔQ)I,J,K
(BΔQ)I,j+1,K=(B+ΔQ)I,J,K+(B-ΔQ)I,J+1,K
(BΔQ)I,j,K=(B+ΔQ)I,J-1,K+(B-ΔQ)I,J,K
(CΔQ)I,J,k+1=(C+ΔQ)I,J,K+(C-ΔQ)I,J,K+1
(CΔQ)I,J,k=(C+ΔQ)I,J,K-1+(C-ΔQ)I,J,K
Definition
Wherein
Respectively matrix A, B, the maximum of C characteristic value absolute value, i.e. spectral radius, herein
χ=1.01 are taken, this spline equation, which can be arranged further, is：
Have again
A+-A-=rAI B+-B-=rBI C+-C-=rCI
Note
Then have：(N+U+L)ΔQn=RHS
Obtained by approximate LU decomposition：(N+L)N-1(N+U)ΔQn=RHS
So full scale equation can be solved by following two steps forms：
C is initial and boundary condition
Primary condition
Initial flow-field takes convergence flow field during isothermal wall (T=300K)；
Entrance boundary
Free inlet flow conditions are in the light of actual conditions given in upstream boundary；
Outlet border
Flow variables extrapolation method is used in downstream boundary；
Object plane border
Object plane temperature takes fluid and structure interface wall surface temperature, and normal pressure gradient is 0.When taking full catalysis wall condition
Atomic component, that is, the mass fraction for giving air to flow are free of in approximating assumption chemistry constituent element；The vacation when taking non-catalytic wall condition
If object plane material is 0 on the normal direction gradient of no influence that chemically reacts, i.e. constituent element mass fraction.
(5) according to the geometrical model and material of testpieces, virtual test part FEM heat transfers are set up in finite element analysis instrument
Model, is calculated by following heat transfer equation, obtains the wall surface temperature T of the testpiecessw；
Heat transfer equation is：
Wherein, ρ is structure effective density, and c is effective specific heat, and T is temperature, kx,ky,kzFor x, y, having on tri- directions of z
Imitate the coefficient of heat conduction；
Initial and boundary condition：
Primary condition is：T(x,y,z)|T=0=300K；
Boundary condition：Fluid and structure interface face heat flow density take step (4) to calculate and obtained and interpolation is in structural model
On heat flow density q*,
The other walls of structural model take adiabatic wall；
(6) formula is passed throughBy wall surface temperature TswEnter row interpolation, be used as step
(4) wall heat flux density q boundary condition, wherein T are solved ini,j,1The temperature obtained for fluid boundary (i, j, 1) unit interpolation,
Ti+1,j,1,Ti1,j,1,Ti,j+1,1,Ti,j-1,1Respectively construction unit projects obtained temperature on element of fluid, and Fig. 2 is structure list
Member and element of fluid corresponding relation schematic diagram, wherein background are fluid grid compared with fine grid；
Pass through formulaWall heat flux density q is entered into row interpolation, as seeking wall surface temperature T in step (5)sw
Boundary condition, wherein, qn,snHeat flow density and cellar area on respectively element of fluid n,siRespectively construction unit
Heat flow density and cellar area on i；
The time step that the present invention is calculated using structural thermal characteristic time Δ t as coupling, in each of Structure Calculation
In time step, it is believed that flow field is transient stability.Specific practice is：
A. pulsatile flow field is tried to achieve using 0 moment structure boundary temperature as boundary condition；
B. in the case of the flow field at 0 moment and object plane heat flux distribution, structure heat transfer governing equation is solved, 0- Δs t is obtained
The Temperature Distribution of period inner structure；
C. using Δ t structure boundary temperature as boundary condition, the steady flow condition of Δ t is tried to achieve；
D. in the case of the flow field of Δ t and object plane heat flux distribution, heat transfer governing equation is solved, Δ t-2 Δs t is obtained
The Temperature Distribution of period inner structure, then repeatedly process above calculates, until simulation blowing test terminates.
Here it is the calculation process of virtual heat test fluid structure interaction mode；
(7) according to the virtual heat test fluid structure interaction mode obtained in step (6), virtual heat test is carried out, that is, simulates wind
Hole blowing test, obtains time and space distribution and the time and space of stress of time and space distribution, the displacement of testpieces temperature
Distribution；
(8) what the result and the virtual blowing test of progress that actual experimental part is blowed to experiment in true wind-tunnel were obtained
As a result it is compared, if comparison result (typically provides scope within 10%) within preset range, then it is assumed that described
Virtual heat test fluid structure interaction mode is accurate；If comparison result is outside preset range, then it is assumed that the virtual heat test stream
Gu coupling model is inaccurate, the virtual heat test fluid structure interaction mode is modified, return to step (4).Wherein Fig. 3 is void
Intend blowing checking numerical results and contrast situation with true blowing test, Fig. 3 (a) is virtual blowing test result, and Fig. 3 (b) is true
Real arc tunnel result of the test, axis of abscissas is test period, and axis of ordinates is testpieces (model) central point temperature, contrast card
The bright invention can accurately simulate arc tunnel blowing test.
The computational fluid dynamics instrument is CFD++ or FASTRAN.
The finite element analysis instrument is ANSYS or ABAQUS.
Described that virtual heat test fluid structure interaction mode is modified, specific method is：
(a) to CFD model amendment, fluid grid yardstick is adjusted；
(b) to testpieces FEM heat transfer model amendments, structured grid yardstick is adjusted；
(c) formula is usedThe heat flow density q on fluid and structure interface face is corrected, to ensure in fluid
With the structure interface face conservation of energy.
Claims (4)
1. a kind of virtual thermal test method based on CFD and FEM technologies, it is characterised in that step is as follows：
(1) thermal environment to hypersonic aircraft is calculated, and is specially：Hypersonic aircraft outer surface is subjected to region
Divide, be divided into Vehicle nose's spherical area and aircraft fuselage plane domain, for aircraft spherical area, thermal environment is calculated
Carried out by formula：
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In formula：Q is heat flow density, ω=0.52, ρswFor the density of aircraft wall gas；μswFor the viscous of aircraft wall gas
Property coefficient, Pr=0.71, Le ∈ [1.0,2.0], ρsFor the gas density in stationary point, μsFor the viscosity of the gas in stationary point, hDFor
Dissociation enthalpy, hsFor stagnation enthalpy, hswFor wall enthalpy；For the velocity gradient at stationary point, obtained from the Newton's formula of amendment,
Calculation formula is：
RoFor radius of curvature, psFor stagnation pressure, p∞For far field force；
For aircraft fuselage plane domain, thermal environment is calculated to be carried out by equation below：
When aircraft surface flow field is in laminar condition,
When aircraft surface flow field is in turbulence state,
In formula：For the Reynolds number estimated under reference conditions, ρ is far field density, UeFor reference velocity, x is with reference to length
Degree, gc=32.174, μ are to refer to viscosity, τm=1, hrTo recover enthalpy；
(2) boxed area is chosen on the thermal protection shield of hypersonic aircraft surface as testpieces, by the testpieces in three-dimensional
Geometric Modeling is carried out in modeling tool；
(3) determine to carry out the wind-tunnel that virtual heat test is used, the wind-tunnel needs to meet：A, wind tunnel nozzle diameter are more than testpieces bag
1.2 times of network size, b, the maximum of wind tunnel nozzle outlet hot-fluid are more than aircraft thermal environment calculating in step (1) and obtain hot-fluid
1.2 times；
When the testpieces chosen position is Vehicle nose, the maximum of wind tunnel nozzle outlet hot-fluid, which is more than in step (1), to fly
1.2 times of row device spherical area thermal environment hot-fluid；When the testpieces chosen position is aircraft fuselage plane domain, wind-tunnel spray
The maximum of pipe outlet hot-fluid is more than 1.2 times of aircraft fuselage plane domain thermal environment hot-fluid in step (1)；
(4) virtual arc tunnel CFD model is set up in computational fluid dynamics instrument, under Cartesian coordinates, passes through institute
The compressible Reynold's average NS equation of three-dimensional non-steady that virtual arc tunnel CFD model solves thermal chemical reaction ideal gas is stated,
The equation is：
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WhereinFor conservation variable, t is the time,For x, y, the nothing on tri- directions of z glues the flux of vector,
For x, y, the sticky momentum flow vector on tri- directions of z obtains wall heat flux density q；
(5) according to the geometrical model and material of testpieces, virtual test part FEM heat transfer moulds are set up in finite element analysis instrument
Type, is calculated by following heat transfer equation, obtains the wall surface temperature T of the testpiecessw；
Heat transfer equation is：
Wherein, ρ is structure effective density, and c is effective specific heat, and T is temperature, kx,ky,kzFor x, y, effective heat on tri- directions of z
The coefficient of conductivity；
(6) formula is passed throughBy wall surface temperature TswEnter row interpolation, as in step (4)
Solve wall heat flux density q boundary condition, wherein Ti,j,1The temperature obtained for fluid boundary (i, j, 1) unit interpolation,
Ti+1,j,1,Ti-1,j,1,Ti,j+1,1,Ti,j-1,1Respectively construction unit projects obtained temperature on element of fluid；
Pass through formulaWall heat flux density q is entered into row interpolation, as seeking wall surface temperature T in step (5)swSide
Boundary's condition, wherein, qn,snHeat flow density and cellar area on respectively element of fluid n,siOn respectively construction unit i
Heat flow density and cellar area；
The time step calculated using the structural thermal characteristic time as coupling, iterative cycles iterative step (4) and step
(5) the virtual heat test fluid structure interaction mode just obtained；
(7) according to the virtual heat test fluid structure interaction mode obtained in step (6), virtual heat test, i.e. blasting is carried out and is tried
Test, obtain the time and space distribution and the time and space distribution of stress of time and space distribution, the displacement of testpieces temperature；
(8) actual experimental part is blowed to the result of experiment in true wind-tunnel with carrying out the result that virtual blowing test is obtained
It is compared, if comparison result is within preset range, then it is assumed that the virtual heat test fluid structure interaction mode is accurate；If
Comparison result is outside preset range, then it is assumed that the virtual heat test fluid structure interaction mode is inaccurate, to the virtual heat examination
Test fluid structure interaction mode to be modified, return to step (4).
2. a kind of virtual thermal test method based on CFD and FEM technologies according to claim 1, it is characterised in that：It is described
Computational fluid dynamics instrument is CFD++ or FASTRAN.
3. a kind of virtual thermal test method based on CFD and FEM technologies according to claim 1, it is characterised in that：It is described
Finite element analysis instrument is ANSYS or ABAQUS.
4. a kind of virtual thermal test method based on CFD and FEM technologies according to claim 1, it is characterised in that：To void
Intend heat test fluid structure interaction mode to be modified, specific method is：
(4.1) to CFD model amendment, fluid grid yardstick is adjusted；
(4.2) to testpieces FEM heat transfer model amendments, structured grid yardstick is adjusted；
(4.3) formula is usedCorrect the heat flow density q on fluid and structure interface face, to ensure in fluid and
The structure interface face conservation of energy.
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