HyperFLOW软件非结构网格亚跨声速湍流模拟的验证与确认

计算流体力学(computational fluid dynamics,CFD)数值模拟在航空航天等领域发挥越来越重要的作用,然而CFD数值模拟结果的可信度仍然需要通过不断地验证与确认来提高.本文给出了从制造解精度测试、简单到复杂外形湍流模拟网格收敛性研究等三个方面开展CFD软件验证与确认的方法,并对自主研发的CFD软件平台HyperFLOW在非结构网格上模拟亚跨声速湍流问题的能力进行了验证与确认.首先通过基于Euler方程和标量扩散方程的制造解精度测试,分别验证了HyperFLOW在非结构网格上对Euler方程和黏性项的求解精度,结果表明其能够在任意非结构网格上达到设计的二阶精度. 其次,通过NASATurbulence Modeling Resource中的湍流平板、二维翼型近尾迹流动、二维Bump等几个典型的亚声速湍流算例的网格收敛性研究,量化考察了数值结果的观测精度阶和网格收敛性指数,并与国外知名CFD解算器CFL3D,FUN3D的计算结果进行了对比,验证了HyperFLOW对简单湍流问题的模拟能力,且具有良好的网格收敛性和计算精度(阶). 最后,通过NASA CommonResearchModel标模定升力系数的网格收敛性研究和升阻极曲线预测,验证了软件在复杂外形亚跨声速湍流流动数值模拟中也具有良好的可信度. 

VERIFICATION AND VALIDATION OF HYPERFLOW SOLVER FOR SUBSONIC AND TRANSONIC TURBULENT FLOW SIMULATIONS ON UNSTRUCTURED/HYBRID GRIDS1)

Computational fluid dynamics (CFD) is playing a more and more important role in aerospace and relevant industries. While the credibility of CFD numerical simulation requires continuous verification and validation. This paper proposes for CFD solvers a complete verification and validation procedure including rigorous accuracy tests based on the method of manufactured solutions (MMS), simple and complex turbulent flow simulation and grid convergence study. The procedure is implemented on the in-house CFD solver HyperFLOW on verifying and validating its ability on subsonic and transonic turbulent flow simulation. We firstly verified that HyperFLOW can achieve designed second-order accuracy on arbitrary unstructured grids via numerical accuracy tests based on the MMS of the Euler equation and the diffusion equation. Then, simple subsonic turbulent flow cases, such as the turbulent flat plate, the 2D Airfoil Near-Wake and the 2D Bump cases from NASA Turbulence Modeling Resources are taken into consideration for grid convergence tests. Observed accuracy order and grid convergence index are calculated and compared with the results obtained by CFL3D and FUN3D, which verified and validated the accuracy and grid convergence performance of HyperFLOW in simple case simulation. Finally, the NASA Common Research Model in Drag Prediction Workshop VI is simulated with fixed lift coefficient, and grid convergence study is carried out on a series of refined grids. Drag polar is predicted by HyperFLOW and compared with other verified and validated results. It demonstrated that HyperFLOW has good accuracy and grid convergence performance in complex configuration high Reynolds subsonic and transonic turbulent flow simulation on unstructured/hybrid grids.