Using the Propeller Pre-Swirl Stator to Reduce Underwater Vehicle Roll Motion and Increase Propeller Efficiency

Pre-swirl stators can operate as a device to improve the hydrodynamic performance of the propeller and reduce the excess propeller torque on the underwater vehicle. This excess torque on the underwater vehicle with a circular cross-section can cause harmful rolling motion. The most important and influential parameters in the design of these stators are the chord length, distance from the propeller, and angle of attack. In this paper, these parameters are investigated using the Taguchi method and stator design to simultaneously reduce the underwater vehicle roll motion (reduction of excess propeller torque) and increase propeller efficiency using computational fluid dynamics with the help of commercial software STAR-CCM+. To validate the calculations, the numerical simulation results of a B-series propeller are compared with the existing experimental test, the numerical results are obtained with less than ten error percentages compared to the experimental results.  The Grid Convergence Index has also been used to ensure the independence of the results obtained from the mesh. The final stator designed in this paper reduces the total propulsion torque by 44.47% compared to the non-stator mode and improves efficiency by 2.29%. Also, the designed stator reduces the vortex of the blade tip and the propeller hub.