Projects

Through the application of tomographic time-resolved imaging and the utilization of index-matching techniques, our research can overcome previous limitations, enabling high-quality measurements of high-speed flow in circular pipes with inertial spheres. The knowledge gained from our work has wide-ranging applications, from engineering and manufacturing to oil and gas and environmental sustainability, fostering advancements and improvements across various industries.

Time resolved Tomographic PIV in refractive index matched quiescent octagonal tank is used to study the flow characteristics of a sphere rising at terminal velocity. Shake the box is used to estimate the particle fields and flow properties near the sphere. The Lagrangian velocity fields can be used to estimate the pressure fields acting around the sphere. The wake analysis can help understand the transient loads that govern the oscillatory trajectory of the sphere as it rises.

It was found that the inception of attached cavitation on curved surfaces or hydrofoils at incidence is relatively insensitive to the concentration of free stream nuclei due to the local formation microbubbles that act as local nucleation sites. 

We showed that stiff porous media can be modeled as a first-order low pass filter acting on the pressure pulse that propagates through the porous medium following the impingement of normal shock waves. 

High resolution stereo-PIV experiments are performed on pipes in the refractive index round channel to characterize the turbulence properties of the flow, when there is a change in the pipe cross sectional area. Four deferent cases with 45 and 90 degree expansion and contraction are studied. Although a simple problem, it is extremely difficult to image due to the curvature of the pipes, an issue overcome here using refractive index matching.

Our study delves into the evolution of shockwaves downstream of area expansions, unveiling a complex flow field with multiple shock reflections, vortex formations, and interactions. By dissecting these phenomena, we gain profound insights into the mechanisms governing transient feature decay during shock propagation

Fine water films form during gravity-induced oil-water separation. the films persist in the oil for a long time until they break up leading to the formation of fine water droplets that remain suspended in the oil.