Computational analysis of noise sources inside the high speed flow over a generalized bump

The aerodynamic noise sources around a three dimensional bump are studied. Firstly in this paper, validation of the numerical method with ILES using symmetric bump is discussed. Cp distribution on the bump is discussed and ILES simulation result shows good agreement with Visbal's numerical result ¹. The gradient of spanwise velocity fluctuation spectrum of present result agrees with gradient of spanwise velocity fluctuation spectrum of Gwibo Byun's experimental result^2-4. At the inertial sub-range, the gradient of sound pressure fluctuation spectrum of present result agrees with the theoretically-determined gradient. Second, the noise level around the bump which is generalized by geometrical parameters is investigated with LES. On the head of bump, wall pressure fluctuation spectrum has a peak besides at other measuring points' don't have. At the front of bump and the back of bump, SPL becomes large below St = 0.79. Moreover longitudinal vortex at side of head of bump generates the loudest noise for all St number.