Wake Development and Scaling of a Marine Propeller Geometry at High Reynolds Numbers

This study presents an experimental investigation of Reynolds number effects on the performance and wake development of a marine propeller using a high-pressure compressed air wind tunnel. By adjusting Reynolds numbers using a compressed-air wind tunnel (CAWT) facility capable of operating at pressures up to 34 atmospheres, the test environment achieves Reynolds numbers representative of full-scale marine applications. The DTMB 4119 propeller, widely used as a benchmark in prior studies, was tested under varying tunnel pressures and advance ratios to examine scale effects on both overall performance and wake characteristics. Thrust and torque measurements showed minor sensitivity to Reynolds number. However, wake surveys revealed clear Reynolds number-dependent differences in turbulence intensity and wake structure. Sharper vortex features and increased coherence were observed as Reynolds number increases, especially near the hub and tip regions. These results demonstrate the value of using a high-pressure wind tunnel to investigate scale effects of marine propulsor. These findings offer experimental data that can support future model validation and scaling analyses and provide insight into how wake structure evolves with Reynolds number.