Effect of Rake Angle on DTMB Marine Propeller

The marine propeller typically functions within the flow field generated by a water vehicle. Investigations into the geometric parameters of the propeller are commonly conducted under open-water conditions as simultaneously simulating both vehicle and propeller holds several computational challenges. While during operation, this propellant device must face several forces like gravity, hydrodynamic load, and centrifugal force, which cause different problems like cavitation and structural failure, etc. Since these issues affect performance, it necessitates comprehensive analysis. In this study, hydrodynamic analysis is performed by using commercial software STAR CCM+. In hydrodynamic analysis, the effect of the rake angles –5°, 5°, 10° and 15° on hydrodynamic coefficients and efficiency of the DTMB 4119 in the open water is analyzed using Computational Fluid Dynamics (CFD) and the control volume approach. The Shear Stress Transport (SST) k-ω turbulence model is used in Computational Fluid Dynamics (CFD) simulation. Hydrodynamic analysis reveals that the rake angles 5° and 10° cause the open water efficiency of David Taylor Model Basin (DTMB) 4119 to improve by 0.4 to 1.32% with exception of the rake angles –5° and 15°, which possess different effects on efficiency. The angle –5° causes a decrease in propeller efficiency under heavy loading situations (low advance coefficient) apart from a minor fluctuation at light loading conditions (high advance coefficient), while the angle 15° produces a drop in efficiency by higher advance ratios but little variation at lower advance ratios.