Body force modeling for aerodynamic analysis of air intake-fan interactions

Abstract

This paper explores a methodology that allows to represent turbomachinery rotating parts at reduced cost with body forces, by replacing the blades with source terms in the RANS equations. In particular, a procedure to extract a force field from classical RANS single passage computations is compared to analytically constructed body forces. A first application to isolated rotor test cases shows that the RANS-extracted body forces approach offers a good level of accuracy, for both global and local flow quantities, while the analytic method of- fers more flexibility. Furthermore, it is shown that including the blade metal blockage effects in the equations significantly improves the performance prediction of both methods. Finally, the analytic model is applied to an air intake test case, and proves to reproduce with a good level of accuracy the bulk effect of the fan on the nacelle flow, both in terms of global (distortion index) and local (pressure distribution) features.