用PIV方法研究底面粗糙度对类形涡的影响

The flow field of a laboratory-simulated tornado was studied by means of 2-D Particle
Image Velocimetry or PIV technique with the purpose of investigating the effects of roughness on
the near-ground tornado-like vortex structure and its velocity distribution. The results show the flow
regime transition from multi-celled vortices over the smooth surface at a higher swirl ratio to singleor
dual-celled vortices with roughness. Significant difference in velocities and turbulence
characteristics is observed as a result of increasing ground roughness. This work is part of a project
that seeks better understanding of the near-ground flow field and resulting wind-induced loads on
structures in a tornado. 德国LaVision PIV/PLIF粒子成像测速场仪