# Taku Nonomura

Department of Aerospace Engineering, Tohoku University

LARGE-SCALE COMPUTATIONAL AEROACOUSTIC SIMULATIONS OF A SUPERSONIC JET

##### Abstract:

In this presentation, the results of large scale computational aeroacoustic simulations of supersonic jets using Japanese supercomputers including the “K” computer are shown. The results of a supersonic free jet with initially laminar shear layer and initially turbulent shear layer are presented. With regard to the supersonic jet with the initially laminar shear layer, aeroacoustic waves are approximately 10dB affected by its thickness and disturbances. The results show that the cases with the thinner shear layer or with the disturbance have lower sound pressure levels. These results are explained with the linear stability analyses. With regard to the initially turbulent case, the acoustic waves are further suppressed compared with the case with the initially laminar shear layer. In this case, linear growth of shear-layer thickness is observed which might be important for the accurate prediction.