The experimental verification of the numerous models and theories that have been evolved in the past decades is difficult if not impossible to do by conventional experiments. The DPIV technique which has been pioneered in our laboratory can provide temporal and spatial mapping of the flow field in a single plane. We have successfully tested a scanning DPIV system for three-dimensional mapping of flow fields. Also of interest is the development of a DPIV technique based on thermally sensitive liquid crystal particles for the simultaneous velocity and temperature field measurements. The study of unsteady flows is important to the understanding of vortex formation, mixing and flow separation processes, lift enhancement and drag reduction.
Cardiac flow is a typical example of flows that are dominated by massive unsteady flow separation.
We have staged a series of in-vitro experiments to understand and characterize the processes involved in the operation of natural heart valves and flow in the left ventricle. These studies will help us in the design of reliable mechanical heart valves. Mixing in the ocean and in the atmosphere are examples of flows which are dominated by unsteady overturning of stratified layers. As part of our program, we have assembled a tilting tank facility to study mixing processes under controlled stratification and unsteady shear parameters.