An Investigation of Fluctuating Pressure Environment around Rocket Fairing with Different Curvetypes

The surface fluctuating pressure environments of the rocket fairings with different curve types, namely normal spherically blunted cone, power series cone and von Karman cone, are systematically investigated by large-eddy simulations (LES). For all the three curve types, the peak of fluctuating pressure is found at a region where shock/separation bubble interacts at a transonic Mach number. The location of the maximum value is consistent with the time-averaged station of shocks. Compared with the fluctuating pressure environment of normal spherically blunted cone, the range and peak of root-mean square pressure coefficient C_{p_rms} are diminished, with the peak value being decreased by 17% for both power series cone and von Karman cone. In particular, serious fluctuating environment could also be induced by the expansion fan, where significant flow acceleration and deceleration occur. The reattached turbulent boundary-layer develops more quickly for normal spherically blunted cone, with its noise magnitude being 10 dB larger than others.