多场耦合计算平台与高超声速热防护结构传热问题研究

Multi-field Coupled Computing Platform and Thermal Transfer of Hypersonic Thermal Protection Structures

从有限元法(FEM)和有限体积法(FVM)的单元特性出发,提出一种具有局部守恒特性的界面载荷插值方法。采用共享内存技术开发适用于通用有限元和计算流体力学(CFD)软件的多场耦合计算平台,并基于分区耦合方式实现流固耦合传热计算。作为验证,分别将ANSYS与Fluent和CFD-FASTRAN软件进行耦合,计算外壁冷却的喷管和高超声速圆柱绕流的耦合传热问题,结果与实验值吻合良好。针对类X-34飞行器的头部热防护结构(TSP),考虑材料非线性和辐射效应,对高超声速巡航状态下驻点温度和结构冷却系统功率随热防护层厚度的变化规律进行了研究。计算结果表明:驻点温度随热防护层厚度的变化并不明显,而冷却系统功率随热防护层厚度增加急剧降低;此外,材料发射率非线性对结果影响较大。

A multi-field coupled computing platform using multi-zone iteration is developed to solve conjugate heat transfer problems.Based on the element features of the finite element method（FEM） and finite volume method（FVM）,a local conservative remapping method is presented for thermal flux and aerodynamic load interpolation.Shared memory is employed for faster data exchange for the general FEMs/computational fluid dynamics（CFD） software.The problems of conjugate heat transfer for a cooled converging-diverging nozzle and a cylindrical leading edge in hypersonic flow are studied.Effects of mesh density,nonlinear material properties and radiation are considered during the computation,and the results show good agreement with the existing experimental data.The relationships are investigated between the stagnation temperature,cooling power and the thickness of the nose thermal protection structure（TPS） of a quasi-X-34 hypersonic vehicle under hypersonic cruise conditions.The results indicate that the thickness variations exhibit no significant influence on stagnation temperature,while the cooling power drops sharply as the thickness increases.Furthermore,the nonlinear material emission pro-perties have significant influence on the analysis results.