A Study on the Wake Evolution of a Set of RIM-Driven Thrusters

In the current paper, high-fidelity improved delayed detached-eddy simulations (IDDES) using OpenFOAM library are employed to characterize performances and wake dynamics of RIM-driven thrusters. Despite their relatively old conception, this type propulsors has gained attention only recently thanks innovative manufacturing technologies materials, which finally have made possible practical implementation. Fostered by stringent regulations on radiated noise emissions enforced in protected areas, they also replacing conventional thrusters main propulsors. By mitigating tip vortex cavitation and, more general, reducing strength vortices, indeed, these may grant a reduction induced pressure pulses without excessively sacrificing efficiency equivalent ducted propellers replace. To provide proof this, three different (one four-bladed, two six-bladed) analyzed compared reference decelerating propeller delivering same thrust at identical functioning conditions. The evolution trailing wakes propulsors, role leakage vortex, nozzle destabilizing effects, highlighted, superior thrusters, terms less intense discussed. Near-field pulses, as measure noise, compared, showing sound levels selected RIM up 15 dB (non-cavitating case) with respect propeller.