细长旋成体大迎角绕流的背涡结构与压力脉动特性

在亚临界流动范围内,通过尖拱细长旋成体在无侧滑状态下的脉动压力测量,对大迎角下细长旋成体非对称背涡结构沿轴向的压力脉动特征进行了研究分析,揭示了压力的脉动幅度与频率沿旋成体轴向的变化规律及其与背涡结构之间的对应关系,并对压力脉动特征沿轴变化的原因进行了初步探讨.

Vortices structure and pressure fluctuation characteristics of the flow over slender body at high angles of attack

In order to study the pressure fluctuation characteristics of the flow over slender body at high angels of attack, in this paper, an experimental of measurement of pressure include time-averaged pressure and fluctuation pressure has been carried out in subcritical Reynolds number range. The pressure fluctuation on both sides along the axis of the cylinder were compared to the cross-section vortices structure, which educed by the measurement of mean pressure based on the physical model of asymmetric vortices. Three conclusions have been made, the vortices structure pressure fluctuation magnitude of slender ogive-cylinder is increasing, and the corresponding frequency is deceasing as the value of x/D is increasing in general.Secondly the pressure fluctuation amplitude in the lower location vortex is greater and the frequency is lower than the other side on each section. The based reason for the changing of pressure fluctuation characteristics is the alternately vortex shedding along the slender cylinder axis.