A parallel three-dimensional computational aeroacoustics method using nonlinear disturbance equations

This paper describes the application of a three-dimensional computational aeroacoustics (CAA) methodology to the prediction of jet noise. The technique has been implemented using parallel computers. In this approach the nonlinear disturbance equations are solved in a conservative form using a finite-difference based technique. A fourth-order optimized dispersion relation preserving scheme is used for spatial discretization and a fourth-order classical Runge-Kutta scheme is employed for temporal discretization. The three-dimensional CAA code has been parallelized using a domain decomposition strategy in the streamwise direction. The calculations are carried out on both IBM-SP2 and SGI Power-Challenge parallel computers using message passing interface routines to facilitate exchange of boundary data between adjacent nodes (processors). Excellent parallel performance has been obtained using the present code. Acoustic results are presented for a perfectly expanded supersonic axisymmetric jet under harmonic and random inlet conditions. Results are given for both the instantaneous and averaged flow and acoustic variables. Comparisons are made between the predictions and experimental data.