物理学报Issue(13)：1-6,6.DOI:10.7498/aps.63.134701
基于NPLS的超声速后台阶流场精细结构及其非定常特性*
Fine structures and the unsteadiness characteristics of sup ersonic flow over backward facing step via NPLS
摘要
Abstract
In a low-noise supersonic wind tunnel at a Mach number 3.4, visualization of flow structure around backward facing step (BFS) with a 3 mm high step is carried out via schlieren and nano-tracer-based planar laser scattering (NPLS) respectively. The time-averaged flow characteristic of the reattachment region and the rich instantaneous structures of the redeveloping boundary layer are both revealed. By contrasting the NPLS images at different times, the unsteady evolvement characteristic of the coherent vortices in the redeveloping boundary layer is discussed. And the results are compared with the schlieren of Mach 4.2 and the prior data published. Results indicate that with either of the two flow visualization ways, the shock waves and the expansion waves can be captured; however, the NPLS technique has the obvious advantages to reveal the instantaneous structures on a small scale in a certain section plane with a time resolution of 6 ns and spatial resolution about micron magnitude;under the flow condition in this contribution, the growth rate of redeveloping boundary layer is 0.07519; the characteristic time is around 10 µs of the hairpin vortex shedding. At the same expansion rate, the reattachment occurs later with increasing Mach numbers, while if the expansion rate increases, the reattachment occurs earlier, and the flow turn angle is larger.关键词
超声速/后台阶/再附/重新发展边界层Key words
supersonic/backward facing step/reattachment/redeveloping boundary layer引用本文复制引用
朱杨柱,易仕和,孔小平,全鹏程,陈植,田立丰..基于NPLS的超声速后台阶流场精细结构及其非定常特性*[J].物理学报,2014,(13):1-6,6.基金项目
国家自然科学基金(批准号:11172326,11302256)、湖南省研究生科研创新项目(批准号：CX2013B002)和国防科技大学优秀研究生创新项目(批准号：B130103)资助的课题.@@@@Project supported by the National Natural Science Foundation of China (Grant Nos.11172326,11302256), Hunan Provincial Innovation Foundation For Postgraduate, China (Grant No. CX2013B002), and the Innovation Fund for Standout Graduate Students of NUDT, China (Grant No. B130103) （批准号:11172326,11302256）
