Effective visualization of Stereo PIV vector fields of a turbulent boundary layer

Stereo PIV datasets have three dimensional information over a plane, from which multiple quantities can be derived at each point. The task of visualizing these different parameters simultaneously is challenging, and this inhibits our ability to analyze and derive firm conclusions about the physics of the flow. Presently, the common approach is to view each parameter separately in different images. Such an approach is very inefficient, especially for large fields of view where many important structures and features co-exist. In this paper we discuss several different ways in which the primary quantities can be viewed simultaneously in the same image. The simplest method is to use different colors for each parameter and to overlay all the different colors on one image. The limitations of such an approach will be described. Other methods considered involve using texture generated from a line integral convolution (LIC) algorithm to convey instantaneous velocity direction and magnitude. Animated texture is also described, together with variants involving combined color and out-ofplane height. The use of height in tandem with color and animated texture is a useful method in distinguishing the different parameters in the regions of overlap. Visualization of PIV data–under review for publication in Journal of Turbulence 2