科研之友
微信
新浪微博
Facebook
分享链接
摘要
The benefits of analyzing multiple interferogram images obtained using oil-film interferometry in order to determine wall shear stress are assessed. Both dual-and multi-image analysis approaches are implemented and compared to standard single interferogram approaches. Each of the analysis approaches is derived from the thin oil-film equation. To assess the different implementations, both experimental interferograms and simulated oil films are used. The simulations determine the oil-film height as a function of space and time by solving the thin oil-film equation subject to a known wall shear stress distribution, whereas experimental interferograms were obtained in a turbulent flat plate boundary layer. The results of analyzing these data with the three different analysis approaches suggest that they all work equally well when test conditions are approximately steady. For tunnels with long transients at startup or when multiple test conditions need to be measured in a single run, the multi-image approach is recommended.
- 出版日期2013-12
