Experimental study on hydrodynamic and cavitation performance of contra-rotating podded propulsors under deflected conditions

Experimental studies were conducted on the hydrodynamic characteristics and cavitation behavior of contra-rotating pod thrusters with different deflection angles (0°, ±5°, and ±10°) in a cavitation wind tunnel. Measurements included the thrust and torque of the fore and aft propellers, and the total force on the propulsor system. The experimental data reveal that the thrust and torque coefficients of the fore propeller continue to increase with deflection angle, and the aft propeller shows a similar ascending trend. The cavitation patterns on fore and aft propeller blades demonstrate periodic fluctuations. Wake vortices shed from the fore propeller propagate downstream and interact with the aft propeller blades, forming extensive cavitation bubbles on the surfaces. The overall wake dynamics of the propulsor are determined by the combined strength of the fore and aft propeller vortices. The results indicate that the deflection angle has a significant influence on hydrodynamic performance and cavitation behavior.