Towards High-Order Large Eddy Simulation of Aero-Thermal Flows for Turbomachinery Applications

Abstract

The solution accuracy and computational efficiency of high order Large Eddy Simulation (LES) solvers are evaluated on two benchmark open literature blade cascade problems. The first problem concerns wake development in the T106A low pressure turbine cascade [1]. The second problem examines the effect of free-stream turbulence on heat transfer from the VKI first stage high pressure turbine vane [2]. The calculations are performed with two independently developed high order LES solvers using completely different numerical algorithms. The first solver FDL3Di [3] was originally developed at the Airforce Research Laboratory (AFRL) and employs structured overset grids. It uses a sixth order compact finite difference scheme in space along with an implicit Beam-Warming scheme for time marching. The second solver, hpMusic, is developed at the University of Kansas [4]. This is a variable order (up to sixth order) unstructured grid solver employing a discontinuous formulation known as flux reconstruction (FR) / correction procedure via reconstruction (CPR) [5]. The computational grids used are independently tuned for each application. The solvers are benchmarked against experimental data for wake development and blade heat transfer coefficient. Further physical insights in to the test cases are also obtained, filling gaps in experimental results, especially for the VKI problem.