Time resolved 3D passive scalar concentration-field imaging by laser induced fluorescence (LIF) in moving liquids

This paper discusses the experimental setup of a 3D LIF imaging facility. T he advected scalar concentration field of a LIF dye is digitized quasi-inst antaneously. The x- and y-resolution are determined by the camera optic, th e z-resolution by the scan process. In the absence of scan noise, spatial r esolution can be designed to be equal in all three directions, The thus obt ained 3D field can be used as input signal for an optical flow measurement technique. The scope of the imaging is mainly constrained by the local Reyn olds number of the flow and the state of current high-speed digital cameras and laser scanners. The reciprocal relationship of the important parameter s is discussed along with some implementational examples for the turbulent free jet.