Large Eddy Simulation of Marine Propulsors in Crashback

Flow around a marine propulsor under crashback operating condition is computed using the large eddy simulation methodology. The incompressible NavierStokes equations are simulated in a rotating frame of reference that rotates with the propulsor. A nondissipative and robust finite volume method developed by Mahesh et al. (2004) is used on unstructured grids. The simulation yields good mean values of unsteady loads as compared to experiments. Also, good agreement with experimental results is observed in circumferentially averaged flow fields. Time averaged flow fields are further investigated. Two quantities for pressure contributions to thrust and side-force are introduced to more clearly understand where thrust and side-force originate. Thrust and side-force are seen to be mainly generated from the suction side of the leading edge of propulsor blades. Conditional averages are performed to obtain quantitative information about the complex flow physics of high or low thrust and high or low side-force.