A Large-Eddy Simulation Study of Unsteady, Vortex Interactions in the Blade Tip Region of a Ducted Propeller

The three-bladed, ducted propeller David Taylor Model Basin (DTMB) 5407 has been extensively studied experimentally in uniform flow at varying Reynolds numbers. Large-eddy simulation (LES) utilizing a novel, unstructured overset grid methodology, developed by Horne and Mahesh [J. Comput. Phys (2019) 376:585-596], is used to study the highly unsteady flow field of this propeller at Re=1.4×10⁶ and multiple advance ratios J. Vortex interactions downstream of the blade tip region have been experimentally shown to cause high flow unsteadiness and large pressure fluctuations crucial to cavitation inception. The simulation results are compared to the experiment. The tip-leakage vortex and other secondary vortices essential to these interactions are studied as they evolve. Details of the flow field and the resulting vortex interactions are discussed.