约束流体3C-2D 速度场的数字高速全息测量
In the last years, several techniques have been developed and improved in such a way that it ispossible to measure the three velocity components in a flow. Some techniques as Stereoscopic PIV orholographic PIV are well known. Others, like tomographic PIV started to develop more recently.Stereoscopic Particle Image Velocimetry (SPIV) or Tomographic PIV need a complex set-up, involving flowvisualization with several cameras, and present important restrictions when applied to confined liquid flows.Others like Holographic PIV cannot be applied in flows with a high particle density. Here a new technique,called High Speed Digital Image Plane Holography has been developed for the measurement of the threevelocity components in a complex geometry brain aneurysm model using a configuration similar to regularPIV. This was done by using a two cavity high speed laser, one double frame high speed camera and normalvisualization. The two in-plane velocity components were obtained from the holograms reconstructedintensity distribution using a PIV analysis. The out-of plane component was obtained from the reconstructedphase differences using an interferometric method. Due to the laser short coherence length, a portable andcompact system has been built in order to be able to the measure larger fluid areas.