Abstract
The purpose of this paper is to investigate the flow mechanism for maximum negative pressure on the upstream area of an elliptic structure by LES analysis, when the oblique flow attacks. First the present LES model is validated for the prediction of the pressure characteristics on a three-dimensional elliptic structure in boundary-layer turbulence through comparison with the experimental data. Next, the flow characteristics which induce the maximum negative pressure are investigated by using the computed results. Furthermore, in order to clarify the fundamental flow characteristics associated with occurrence of the maximum negative pressure on an elliptic cylinder, LES analysis for a two-dimensional elliptic cylinder in uniform flow is carried out as a function of the Reynolds number and the wind direction. As a result, it is clarified that the characteristics of the flow separation and reattachment associated with the change in the curvature of surface of an elliptic cylinder cause the maximum negative pressure.
