Numerical Analysis into the Effects of the Unsteady Flow in an Automotive Hydrodynamic Torque Converter

Abstract

In this paper the characteristics of a three dimen- sional, incompressible, turbulent, unsteady flow within a one- stage two-phase automotive hydrodynamic torque converter was numerically simulated and analyzed. For the investigation the finite volume method has been employed. The commercial 3D Navier-Stokes Software CFX of ANSYS Inc. was used to investigate the flow inside a torque converter. The software solves the incompressible Reynolds-Averaged- Navier-Stokes (RANS) equations on the entire flow domain using the k- turbulence model. To compare the simulation with experimental results, the nondimensional characteristics were used. The flow field is determined by the blade position of both rotors, which have different rotating velocities. Discrepancies between the steady and unsteady simulations were found and discussed. The unsteady flow at the pump exit and turbine inlet will be analized through instantaneous flow fields in a period. Index Terms—hydrodynamic torque converter, CFD, un- steady flow, fluid flow simulation.