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The influence of a typical stator and support arm on the performance of an automotive engine cooling module is evaluated. Measured lift (CL) and the drag (CD) coefficients are compared for a typical stator and support arm under real unsteady inlet conditions. These inlet conditions are based on Laser Doppler Velocimetry (LDV) data taken in the flow downstream of an automotive cooling fan. The quality of the experimental results is assessed upon comparison with the well-established flat plate data. It is found that inlet conditions dramatically affect the aerodynamic performance of both the stator and the support arm. A suitable range of inlet conditions on which to base the design is presented. The second objective of the current study is to establish accurate numerical simulation guidelines for future fan designs. Various turbulence models are evaluated based on comparison with experimentally measured data for a stator and a support arm at various angles of attack.

A numerical model to assess the aerodynamic performance of typical automotive cooling fan stators or support arms is presented. Under real operating conditions, the flow over stators or support arms resembles bluff body flow. Hence, the time and spatial resolution are selected based on previous numerical simulations for the flow around a normal flat plate. Turbulence modeling is based on the Unsteady Reynolds-averaged Navier-Stokes (URANS) equations retaining the Boussinesq eddy-viscosity hypothesis. The ability of the URANS model to predict the periodic nature of the flow is demonstrated here. Furthermore, comparison with experimental data shows that the proposed numerical model can predict the global flow parameters, namely lift and drag within good accuracy. As a first attempt to assess the interaction of the cooling fan with its system environment, the proposed numerical model is expanded to model the interaction of the fan blades with the adjacent stators or support arms.