COMPUTATIONAL SIMULATIONS OF FORE AND AFT RADIATION FROM DUCTED FANS*

In this paper, we extend the work of Ozyoruk and Long, for predicting farfield noise from ducted fans using a higher order coupled Euler/Navier-Stokes solver along with a Kirchhoff formulation, to full engine configurations on distributed parallel computers. Incorporating the exhaust along with the inlet raises many issues relating to appropriate grid topologies, multigrid acceleration and the unsteady numerics. These issues are addressed in this paper and simulations pertaining to a realistic engine geometry are presented. Qualitative comparisons are in good agreement with results from a frequency domain code, pertaining to radiation from a dipole in a cylinder. Simulations relating to radiation from an engine geometry, and with and without the centerbody, with and without mass flow are also shown