基于单相机光场PIV的逆压湍流边界层测量  

Volumetric measurements of an adverse-pressure-gradient turbulent boundary layer using single-camera light-field PIV

作　　者：赵洲 丁俊飞 施圣贤 Zhao Zhou;Ding Junfei;Shi Shengxian(Turbomachinary Research Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

机构地区：[1]上海交通大学机械与动力工程学院叶轮机械研究所,上海200240

出　　处：《实验流体力学》2019年第2期66-71,共6页Journal of Experiments in Fluid Mechanics

基　　金：国家自然科学基金项目(11472175;11772197)

摘　　要：作为一种新兴的体三维粒子图像测速技术,光场单相机三维粒子图像测速技术(Single-Camera LightField Particle Image Velocimetry,LF-PIV)能够仅用单个相机获得三维速度场,其结果已在许多复杂三维流动测量中得到验证。LF-PIV的优势主要在于其紧凑简便的硬件设备以及对光学窗口较宽松的要求。应用LF-PIV技术对一个自相似的逆压湍流边界层(Adverse Pressure Gradient Turbulent Boundary Layer,APG-TBL)进行测量,该实验在澳大利亚莫纳什大学(Monash University)航空航天与燃烧湍流研究实验室(Laboratory for Turbulence Research in Aerospace and Combustion,LTRAC)水洞中完成。实验对远、近壁面测量所得到的各600组瞬态三维流场数据进行分析验证,并与相同工况下的2D-PIV实验结果对比,证明基于DRT-MART重构技术的LF-PIV能够进行基本的湍流边界层测量。As a novel volumetric particle image velocimetry technique, Single-Camera Light-Field PIV (LF-PIV) is able to reconstruct three-dimensional flow fields using a single camera. The merits of LF-PIV lie in its concise hardware setup and minimum optical access requirement. Its capability has been proved in many experimental investigations. In this study, LF-PIV is used to measure a self-similar Adverse Pressure Gradient Turbulent Boundary Layer (APG-TBL). Experiments are performed in a large water tunnel at the Laboratory for Turbulence Research in Aerospace and Combustion (LTRAC), Monash University. Twenty independent batches of light-field PIV images are captured for both inner and outer flow, each consisting of 250 instantaneous image pairs. Instantaneous 3D velocity fields are reconstructed with the GPU accelerated DRT-MART and 3D cross-correlation methods and compared with two-dimensional PIV (2D-PIV) results. Preliminary results show that though limited by the experiment conditions and PIV algorithms developed in 2016,similar accuracies to 2D-PIV are achieved near and above the boundary layer. With the volumetric calibration method that compensates optical distortions caused by lens defect and misalignment between the Microlens Array (MLA) and image sensor, the resolution of LF-PIV is greatly improved.

关 键 词：光场PIV 单相机三维PIV 湍流边界层 负压力梯度 

分 类 号：V211.7[航空宇航科学与技术—航空宇航推进理论与工程]