在激波以及激波边界层相互作用这类含激波的复杂流场中,流场结构具有明显的三维特征.研究这类流场,采用纹影、阴影和干涉等传统流动显示技术空间分辨率较低,难以分辨流场的三维特性.基于纳米示踪的平面激光散射技术(nano-tracer planar laser scattering,NPLS),是作者近年来开发的一种新的研究超声速流场的测试与显示技术,可对超声速复杂三维流场进行高时空分辨率流动显示与测量.NPLS技术的特点使其成为测量激波复杂流场的有力手段.近年来,作者以NPLS技术为主要手段,对航空航天领域典型的激波复杂流场进行了试验研究,包括超声速弹头绕流、超声速混合层、超声速边界层,以及激波边界层相互作用流场,显示出NPLS技术在激波复杂流场精细测试与流动显示中优势.本文简要介绍NPLS技术在激波复杂流场测量中应用的研究进展.
There are usually three dimensional structure in the complex flow fields involving shock waves and interaction between shock waves and boundary layers.It is of low spatial resolution to study these flow fields using traditional flow visualization techniques,such as schlieren,shadow and interference methods,and the three dimensional characters are usually hard to be identified.The Nano-tracer based Planar Laser Scattering(NPLS) technique is a new method developed recently for the measurement and visualization of supersonic three dimensional complex flow fields.It has achieved spatiotemporal resolution,and is thus a good method for the measurement of complex flow fields involving shock waves.In recent years,mainly with NPLS technique,we have carried out vast experimental research on typical complex flows in the area of aeronautics and aerospace,including supersonic flows over bullets,supersonic mixing layers,supersonic boundary layers and the interaction between shock waves and boundary layers.And advantages of the NPLS technique are clearly revealed in these studies.Process is elucidated in this paper for the application of NPLS technique to the measurement of complex flow fields involving shock waves.