(高)超声速流动试验技术及研究进展

近年来,与高速飞行器相关的(高)超声速流动受到了极大的关注。这类流动所具有的非定常性、强梯度和可压缩性对试验方法和风洞设计技术提出了挑战。超声速纳米示踪平面激光散射(NPLS)技术是由作者所在团队研发的非接触光学测试技术。它能够以较高的空间分辨率来揭示超声速三维流场的一个瞬态剖面的时间解析的流动结构。介绍了NPLS技术以及基于NPLS开发的密度场测量、雷诺应力测量和气动光学波前测量等方法,并回顾了这些技术在超声速边界层、超声速混合层、超声速压缩拐角、激波/边界层相互作用和光学头罩绕流等流动中的应用,清晰地再现了边界层、混合层、激波等典型流场结构及其时空演化特性。另外,为了模拟和研究高空大气条件下边界层自然转捩和超声速混合层的转捩特性,介绍了高超声速静风洞、超-超混合层风洞的设计技术以及层流化喷管的设计方法。

Progress on experimental techniques and studies of hypersonic/supersonic flows

The research of flows associated with the hypersonic aircraft has aroused more and more attention. Experimental techniques and wind tunnel designing methods are challenged when applied to these flows, due to the unstableness, intensive gradients and compression effects. Supersonic nano-tracer planar scattering (NPLS) technique is a non-intrusive optic measuring method proposed by the author''s research group. It can reveal structures of a transient cross-section of supersonic three-dimensional flow field at high spatial and temporal resolution. In this paper, techniques are introduced including NPLS, density measurement, Reynolds stress measurement, aero-optic wavefront measurement based on NPLS. Applications of these techniques on supersonic boundary layer, supersonic mixing layer, supersonic compression-corner flow, shock/boundary layer interaction and supersonic flow passing over an optic cowl are reviewed. Typical flow structures such as boundary layer, mixing layer and shock wave are revealed along with the corresponding temporal evolution characteristics. In addition, to simulate and study the nature transition of boundary layer in the atmospheric conditions and to study supersonic mixing layer transition, the design of hypersonic quiet wind tunnel and supersonic mixing layer wind tunnel are introduced along with the laminarized nozzle designing.