RETRACTED: Numerical and experimental cavitation assessment of near-wake characteristics of hydrodynamic performance characteristics of cavitating flow with and without ultrasonic transducers

Abstract

Abstract The primary objective of this research is to study the cavitating effects of fluid flow past a cylinder. Experimental and numerical investigation is carried out to study the effect of cylinder diameter and its length on the formation of wake cavitation in the upper sub-critical flow regime, which corresponds to Reynolds number (Re) in the range of 2 × 104 to 2 × 105. Additionally, to enhance the cavitation phenomena, an ultrasonic transducer is designed. The commercial software tool, ANSYS Fluent 17.2, is used to simplify three dimensional Reynolds averaged Navier Stokes equation with the compressible fluid flow by considering the pressure-based solver with standard K- ω turbulence model. The Schnerr and Sauer cavitation model is employed to study the cavitation phenomena. Results reported that with an increase in the cavitation number, the size of the wake cavity decreased. Also, the size and the length of the wake cavity depend on the diameter of the cylinder and the size of the step provided. A comparison of the numerical and experimental results shows that the numerical method is able to predict accurately the shape parameters of the natural cavitation phenomena such as cavity length, cavity diameter and cavity shape. The results also indicate the drag coefficient decreases up to 40% when the stepped cylinder size in reduction is observed, provided Reynolds number remains constant. Also, for the plain cylinder the drag coefficient rises by 28% when cavitation number is increased from 0.25 to 0.32.