Flow and Heat Transfer Computations in a Rotating Cavity With Tangential Seal Air Flow

Abstract

Axi-symmetric and three-dimensional CFD models for a rotating open interdisk cavity have been developed to predict flow, heat transfer, windage power loss and cavity air temperatures as a part of the rotor thermomechanical analysis and design life study. The cavity has a tangential (axial and circumferential) seal air flow above it. The rotational Reynolds number is 4.8 × 106 and the non-dimensional seal flow rate is 9.8 × 104. Measured wall temperatures are used as boundary conditions in the model. The axi-symmetric model smears the cavity bolts as 360° continuous rings and therefore ignores the bolts pumping effect. The windage loss calculation from the axi-symmetric model is in good agreement with the experimental data in the literature. The heat transfer coefficient values from the axi-symmetric and three-dimensional models are comparable in most of the regions apart from near the bolts. Also, the three-dimensional model simulates the bolt pumping effects and yields a much higher windage loss value, which in turn raises the cavity air temperature. It is concluded that a three-dimensional model is necessary for an accurate heat transfer analysis.