High-Order Methods for Turbulence Using Strand Grids
A novel high-order method,combining unstructured flux-correction along body surfaces and high-order finite differences normal to surfaces is formulated for high Reynolds number turbulent flows on strand grids.A robust version of the Spalart-Allmaras turbulence model is employed that accommodates negative values of the turbulence working variable.The fluxcorrection algorithm is applied in each unstructured layer of the strand grid,and the layers are then coupled together via a source term containing derivatives in the strand direction.Stranddirection derivatives are approximated to high-order via summation-by-parts operators for first derivatives and second derivatives with variable coefficients.We show how this procedure allows for the proper truncation error canceling properties required for the flux-correction scheme.The resulting scheme possesses third-order design accuracy,but often exhibits fourth-order accuracy when higher-order derivatives are employed in the strand direction,especially for highly viscous flows.The Spalart-Allmaras turbulence model employed within the flux-correction framework sees fourth-order convergence using the method of manufactured solutions.Fundamental validation studies of the turbulent flux-correction method are conducted in two dimensions,using the NASALangley turbulence resource as a means for comparison.Results are presented that demonstrate improvements in accuracy with minimal computational and algorithmic overhead over traditional second-order algorithms.
Strand Grids High-order Methods Turbulence Modeling
Oisin Tong Dalon Work Aaron Katz
Utah State University, Logan, UT, USA 84322
国际会议
The 8th International Conference of Computational Fluid Dynamics, (ICCFD8)(第八届国际计算流体力学会议)
成都
英文
1-19
2014-07-25（万方平台首次上网日期，不代表论文的发表时间）