PIV analysis of opaque flow without using high-tech equipment.

The current study reports PIV (particle image velocimetry) analysis of the transparent and opaque flow using a smartphone camera in ambient light. A typical PIV setup consists of high-speed cameras, synchronizers, and high-energy light sources like pulsed lasers or high-power LEDs, whereas in the present work, we demonstrate that PIV analysis can be possible without sophisticated instruments. Two essential parameters, viz recording speed and interrogation window size, have been optimized for the flow recorded in the mobile camera. The present work describes methods for optimization of recording speed (fps-frames per second) and interrogation window (IW) size for the transparent (water) vortex flow. Further, the velocity profile derived at optimal recording speed and interrogation window size using the PIV analysis have been compared with the Burger vortex model to validate the optimization methods and the parameters. The agreement validates the optimization methods and the parameters. Moreover, the optimized parameters have been used to record and analyze the opaque flow to extend the application potentiality. The finding suggests that the PIV- extracted data of the opaque flow can be compared with the transparent flow, which suggests that PIV can also be used to analyze opaque flow. [Display omitted] • Velocity estimation and comparison of transparent and opaque flow using PIV. • The potential of the PIV technique for the surface flow analysis of opaque flow. • The use of ambient light and a smartphone camera to record the flow. • The study provides a stepwise optimization method for consideration of recording speed and interrogation window size. [ABSTRACT FROM AUTHOR]