Computational Study of the Unsteady Flow due to Wakes Passing Through a Channel
The flow in, and the heat transfer to, turbine cascades are influenced strongly by rotor-stator-interaction causing wakes from the preceding row to pass through the cascade channel. Predictions of this unsteady flow are presented for the idealised case of a plane channel with the wakes generated by cylinders moving past the inlet plane. The calculations are obtained with an unsteady finite-volume method employing the k — ε turbulence model. The calculation procedure is verified first for developing steady channel flow and is then applied to the unsteady passing wake situation for various moving-cylinder-channel configurations. The results show that the passing wakes cause much stronger velocity fluctuations then would be due to turbulence.
KeywordsWall Shear Stress Turbulent Kinetic Energy Unsteady Flow Strouhal Number Rotor Blade
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