The main objective of the present work was to develop a porous media based axi-symmetric bolt protrusion drag and heat transfer model for fast and efficient aero-thermal coupling of a rotor-stator cavity with rotor mounted bolts. Traditionally, detailed non axisymmetric features like bolts, holes etc. are either approximated through windage correlations or ignored which could result in significant difference in disc temperature prediction. Protrusion drag and windage work terms are introduced into the bolt porous zone in an axisymmetric model to simulate non axisymmetric effects of protrusions. The drag, tangential velocity and adiabatic disc surface temperature results from the simplified axisymmetric model are compared with 3D CFD model predictions and experimental data for a range of rotational and throughflow Reynolds numbers. The simplified porous media based models are found to predict the drag and windage heat transfer with reasonable accuracy compared to 3D sector CFD results. However, 3D sector CFD under-predicts the high core flow swirl and mixing of the hot fluid withinthe rotor-stator cavity and also under-predicts the adiabatic disc surface temperature inboard of the bolt, compared to experimental data, particularly for the rotationally dominated flow case. The comparison of disc temperature with measurements for the through flow dominated case of λT=0.2 and Cw = 105 is satisfactory.
Radiation-Conduction Interaction of Steady Streamwise Surface Temperature Variations on Vertical Free Convection
