非正交界面下的插值耦合传热方法

Development of Interpolation Method for Conjugate Heat Transfer in Non-Orthogonal Interfaces

关键词:  耦合传热  非正交界面  插值算法  喷管

Key words:  Conjugate heat transfer  Non-orthogonal interfaces  Interpolation method  Nozzles

摘要:

针对复杂热防护结构，开发了一种求解非正交性流/固界面的耦合传热程序。流体和固体区域采用同一积分、守恒型的RANS(Reynolds-Averaged Navier-Stock)方程，通过有限体积法进行离散求解。为了保证非正交界面上的温度和热流密度连续，提出了一种结合网格周边信息计算界面热流密度的插值方法。利用该插值耦合方法模拟了双层复合平板和喷管的热传导。数值结果表明:该插值方法在空间上具有2阶精度；喷管壁面上的对流换热系数沿轴向先增大后减小，在喉部上游达到最大值，当喷管入口压力增加3.38倍时，对流换热系数的最大值相应增加了3.13倍；喉衬与壳体界面上温度的计算值和试验结果存在一定差异，这是由于本文数值计算未考虑接触热阻引起的。

Abstract:

A conjugate heat transfer (CHT) code has been developed for the complex thermal protection structures with non-orthogonal fluid/solid interfaces. Both fluid- and solid- domains employ the integral and conservative form of the Reynolds-Averaged Navier-Stock(RANS) equations，which are discretized by means of the finite volume scheme. To keep the heat flux and temperature consistent on the non-orthogonal interface，a coupling strategy using the interpolation of information from neighboring cells was proposed to calculate the heat flux on the interface. The heat conduction problems of a two-layer composite slap and nozzles were simulated using the interpolation coupling method. The numerical results indicate that the proposed interpolation method is of 2nd order accuracy in the space. The heat transfer coefficients on the nozzle wall increase and then decrease along the axial direction，reaching maximum values in the upstream of the throat. When the nozzle inlet pressure increases by 3.38 times，the maximum value of heat transfer coefficient increases by 3.13 times，accordingly. The temperature numerical results and experimental data show some differences on the interface between the insert and nozzle housing，which is caused by the neglect of the thermal contact resistance in the current simulation.