高效有限体积方法及其在紧凑快速换热器流/热耦合数值模拟中的应用

This project is a continuation of a cultivation project supported by major research project of the natural science foundation: "high order finite volume method on unstructured meshes and its application in numerical simulation on conjugate heat transfer for turbine (2012 -2014)". Aimed at the follow-up problems of the previous project, two parts of study will be carried out:the first part consideres the construction of high-order accuracy finite volume method of Navier-Stokes(NS) equations and Reynolds-averaged Navier-Stokes(RANS) equations on unstructured meshes. As the viscous term is generally computed by the central difference schemes, we focus on the discretization of the convection term. On the one hand, high-order accuracy reconstruction strategy on unstructured meshes is studied, to guarantee that the final numerical solution can obtain third or higher order in smooth region and has strong stability in is essentially non-oscillation near singular. On the other hand, high-order accuracy conjugate method at interface between fluid and solid is studied, to ensure the continuities of information such as temperature, heat etc. To improve the computational efficiency,the adaptive methods and some acceleration strategies are also discussed; the second part is application of our method in the numerical simulation of conjugate heat transfer, which includes the preparation of the corresponding computer program, the numerical tests of some typical conjugate heat transfer problems of compact fast heat exchanger, and the analysis of numerical results and flow mechanism, etc. The research of this project can provide computational support for the development of the compact fast heat exchanger of aviation engine.

本项目是重大研究计划培育项目“非结构网格高精度有限体积方法及其在涡轮流/热耦合数值模拟中的应用（2012 年-2014 年）”的延续，针对前一项目的后续问题开展两部分的研究：第一部分是对NS方程和雷诺平均NS方程构造高效非结构网格有限体积方法。由于粘性通量多采用中心格式离散，所以重点研究对流通量的离散，一方面研究非结构网格上简单易行的高精度重构策略，使得最终得到的数值解在光滑区域具有三阶及以上精度，在奇异区域具有较强的稳定性，另一方面研究流/固交界面上的高精度耦合方法，保证温度和热流量等信息的连续性，同时讨论一些自适应方法和加速收敛措施以提高计算效率；第二部分是方法在紧凑快速换热器流/热耦合计算中的应用，包括将所构造的方法集成至现有计算程序，对一些典型的换热问题进行模拟，分析计算结果及流动机理等。本项目的研究可为航空发动机紧凑快速换热器的研制提供科学计算支撑。