抄録
In this study, multiobjective design exploration for a rocket launch site is conducted using evolutionary computation with large eddy simulation to understand the acoustic characteristics associated with various launch sites. The launch site is described by curved surface. The flat plate inclined with 45 degree is considered as the reference configuration. The objective functions of multiobjective aero-acoustic design optimization are, 1) minimization of averaged sound pressure level near the payload fairing, 2) minimization of maximum pressure on the curved surface of the rocket launch site, and 3) minimization of the change of the curved surface from the reference configuration. Three-dimensional compressible Navier-Stokes equations are solved with the modified weighted compact nonlinear scheme. The total number of evaluation is 2500, and the evaluation of one generation necessitates the use of 6500 nodes using "K" supercomputer. As the results of the flow field analysis of some characteristic non-dominated solutions show the characteristics of acoustic wave and the location of the maximum gradient of the curved surface.
