Rans, detached Eddy simulation and large Eddy simulation of internal Torque converters flows: A comparative study

Abstract

Comparative analysis among the capabilities of the RANS, DES, and LES models to predict flow and turbulence distribution was conducted to come up with guidelines for hydraulic torque converter (TC) transient simulation. To ensure the accuracy of calculation, the complex geometry of hydrodynamic elements was accurately represented and the computational meshes of the structured hexahedron were appropriately distributed. Wall shear stress, pressure-streamline structure were analyzed. Compared with RANS, the transient vorticity features, including the birth, development, formation of a scroll; transportation along the blade surface; shedding and rupture at the trailing edge could be clearly captured by the LES and DES models. Rothalpy was used to quantitatively evaluate the hydraulic loss and a new computational formula was proposed to predict the efficiency of each element in TC. After the comparison of relative computing time, DES model was proved be a feasible method for efficiently and accurately simulating 3D unsteady turbulent flow of TC.