Hydrodynamic cavitation in non-Newtonian viscoelastic flow

The current work aims to develop a methodology based on an ultra-high-speed imaging system to interrogate water and dilute polymer-based solution flow in the presence of cavitation. The method will help understand the effects of adding drag-reducing agents to a cavitating water flow and investigate any possible cavitation reduction (CR) or cavitation suppression (CS) mechanisms associated with these additives. A mesoscale converging-diverging flow channel with a throat size of 2 mm was designed for this purpose. Two-dimensional particle image velocimetry was used to initially investigate the turbulent characteristics of the flow field. Ultra-high-speed imaging with frame rates up to one million frames per second will be utilized to capture the cavitation regimes’ temporal evolution, obtain time-resolved velocity fields, and calculate the pressure fields using a dynamic tessellation approach. High-frequency pressure signals from the sensors installed downstream in the channel, time-resolved ultra-high-speed images, and pressure fields will be utilized to quantify the strength of shockwaves propagating downstream on the midspan of the channel. The first phase of the experiments was devoted to validating the experimental methodology, for which related discussions are provided here. The second phase focuses on determining the polymer additives’ CR and CS effects by investigating the flow’s turbulence and cavitation characteristics using ultra-high-speed imaging.