Set-Up Analysis and Optimization of CFD Simulations for Radial Turbines

Abstract This paper proposes a CFD method for simulating radial turbocharger turbine flows. A review is presented of the computational model in terms of meshing, mesh movement strategy, and computational algorithm in turbomachinery CFD simulations. A novel local mesh independence analysis is developed for this purpose. This procedure is aimed at distributing the cells more efficiently by selecting suitable cell sizes for the different regions of the domain to optimize the use of the available computational resources. Pressure- and density-based solvers are compared. The influence of the moving-mesh strategy was analyzed, and small differences were observed in the region near the maximum efficiency point, while these differences increased when off-design conditions were considered. Finally, a comparison of the results with data from an experimental test bench shows that the proposed computational methodology can be used to characterize radial turbomachinery. The objective of the analysis and the optimization of the case configuration was to establish some general guidelines for CFD turbomachinery simulations.

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