Numerical investigation of three-dimensional effects of hydrodynamic cavitation in a Venturi tube.

Hydrodynamic Cavitation (HC) is a highly turbulent, unsteady, multi-phase flow that has been useful in many processing applications like wastewater treatment and process intensification and hence needs to be studied in detail. The aim of this study is to investigate the mechanisms driving HC inside a Venturi tube using numerical simulations. The numerical simulations are conducted in the form of both two-dimensional (2D) and three-dimensional (3D) simulations using the Detached Eddy Simulation (DES) model database to simulate the cavitation-turbulence interplay, and the results are validated against high-fidelity experimental data.

Combined suppression effects on hydrodynamic cavitation performance in Venturi-type reactor for process intensification.

Hydrodynamic cavitation is an emerging intensification technology in water treatment or chemical processing, and Venturi-type cavitation reactors exhibit advantages for industrial-scale production. The effects of temperature on hydrodynamic cavitating flows are investigated to find the optimum reaction conditions enhancing cavitating treatment intensity. Results show that the cavitation performance, including the cavitation intensity and cavitation unsteady behavior, is influenced by (1) cavitation number σ (the pressure difference affecting the vaporization process), (2) Reynolds number Re (the inertial/viscous ratio affecting the bubble size and liquid-vapor interface area), and (3) thermodynamic parameter Σ (the thermal effect affecting the temperature drop).

Observations of cavitation erosion pit formation.

Previous investigations showed that a single cavitation bubble collapse can cause more than one erosion pit (Philipp & Lauterborn [1]). But our preliminary study showed just the opposite - that in some cases a single cavitation pit can result from more than one cavitation event. The present study shows deeper investigation of this phenomenon.