This paper discusses the CFD investigation to estimate the cavitation characteristics of the Princess Royal propeller using the RANS-based CFD code Simerics-MP+. The propeller used in the Princess Royal research vessel at Newcastle University was chosen for the present cavitation benchmark study. Accurate prediction of propeller cavitation characteristics is of paramount importance to avoid its adverse effects, such as reduced propulsive efficiency, erosion, and increased noise. Initially, the propeller performance was validated in open water conditions, and then cavitation studies were conducted for different flow conditions based on the advanced coefficient and cavitation number. The equilibrium dissolved gas model (Ding et al., 2011) which accounts for both aeration and cavitation effects, was used to model the cavitation characteristics. The gas present in the fluid can be in various states, such as free, dissolved, or mixed, based on the local pressure. The cavitation bubbles and the propeller performance characteristics obtained from the CFD simulation showed good agreement with the available experimental data.
Cavitation is an unavoidable phenomenon that occurs during marine propeller operation and has a detrimental effect on propeller performance. It involves the formation of vapor bubbles in a liquid medium when the local static pressure falls below the vapor pressure. The marine propeller undergoes various types of cavitation, such as sheet, cloud, bubble, root, face, tip, and hub vortex depending on its blade loading. Cavitation causes various issues in the marine propeller, such as increased underwater radiated noise (URN), blade erosion, reduced propeller performance, and increased hull vibration. The discrete tonal and broadband noise generated due to cavitation constitutes 80–85% of the total ship URN (Ross, 1976). The increased URN due to the cavitating propeller is detrimental to marine life. It hinders the communication ability and migratory behavior of marine mammals (National Research Council, 2003). Cavitation reduction is inevitable to achieve the guidelines set by the International Maritime Organization (IMO) to minimize the URN. The IMO recommends computational fluid dynamics (CFD) approach to predict propeller flow and cavitation characteristics (IMO, 2014). With exponentially increasing computing power, the CFD models can help in the propeller design process to improve their performance. Accurate cavitation modeling using CFD still poses a significant challenge due to large density variation, wide range of bubble size, multiphase flow, compressibility, transient bubble dynamics, etc.