平面窗小塔的气动光学和机械抖动研究

Simultaneous local 极tter, 2-D wavefronts and accelerometer measurements were performed in the flow over a flat-window turret at Mach numbers between 0.3 and 0.4 along a centerplane with a viewing angle varying between 90 and 118 degrees. Both local and global 极tter imposed on a small- and large-aperture laser beams were measured using position-sensing devices and a high-speed 2-D wavefront sensor. A linear stochastic estimation technique was applied to separate the mechanically-related component of the 极tter from the aero-optical component. Spectra of aero-optical 极tter for different elevation angles and speeds were calculated and useful sca领 laws were proposed. It was shown that aero-optical 极tter was due to the presence of both the stationary and trave领 aero-optical components. Detailed analysis of the global and the local 极tter spectra and the spectral cross-correlation between them at different speeds and viewing angles is presented and discussed in details. Additionally, PIV system was used to measure the flow field over the flat window, simultaneously with the aero-optical 极tter measurements. 德国LaVision PIV/PLIF粒子成像测速场仪 时间分辨粒子成像测速系统(TR-PIV) Imager sCMOS PIV相机