전진비가 추진기 후류에 미치는 영향

Abstract

The present study numerically investigated the effect of the advance ratio on the wake characteristics of the marine propeller in the propeller open water test. Therefore, a wide range of the advance ratio(0.2<J<0.8) and the region ranging from the trailing edge to one propeller diameter downstream location are considered to analyze the effect of advance ratio on the evolution of wake in terms of the tip vortices, slip stream and pressure. In order to simulate the incompressible viscous turbulent flow around the propeller, the Reynolds averaged Navier-Stokes (RANS) equations with the turbulence closure model of Model are considered. The three-dimensional vortical structures of tip vortices are visualized by the swirl strength, resulting in fast decay of the tip vortices with increasing the advance ratio. Furthermore, to better understanding of the wake evolution, the contraction ratio of the slip stream for different advance ratios is extracted from the velocity fields. Consequently, the slip stream contraction ratio decreases with increasing the advance ratio and successively the difference of the slip stream contraction ratio between J=0.2 and J=0.8 is about 0.1R.