RANS Simulation of Ducted Marine Propulsor Flow Including Subvisual Cavitation and Acoustic Modeling

High-fidelity Reynolds-averaged Navier Stokes (RANS) simulations are presented for the ducted marine propulsor P5206, including verification and validation (V&V) using available experimental fluid dynamics data, and subvisual cavitation, and acoustics analysis using the modified Rayleigh-Plesset equation along the bubble trajectories with a farfield form of the acoustic pressure for a collapsing spherical bubble. CFDSHIP-IOWA is used with the blended k-ω/k-e turbulence model and extensions for a relative rotating coordinate system and overset grids. The intervals of V&V analysis for thrust, torque, and profile averaged radial velocity just downstream of rotor tip are reasonable in comparison with previous results. The flow pattern displays the interaction and merging of the tip-leakage and trailing edge vortices. In the interaction region, multiple peaks and vorticity are smaller, whereas in the merging region, there is better agreement with the experiment. The tip-leakage vortex core position, size, circulation, and cavitation patterns for σ i =5 also show good agreement with the experiment, although the vortex core size is larger and the circulation in the interaction region is smaller. The simulations indicate globally minimum C p =-σ i =-8.8 on the suction side of the rotor tip at 84% chord from the leading edge and locally minimum C p =-6.4 in the tip-leakage vortex at 8% chord downstream of the trailing edge, whereas EFD indicates σ i = 11 and the location in the tip-leakage vortex core 50% chord downstream of the trailing edge. Subvisual cavitation and acoustics analysis show that bubble dynamics may partly explain these discrepancies.

[1]  Hugh W. Coleman,et al.  Comprehensive Approach to Verification and Validation of CFD Simulations—Part 1: Methodology and Procedures , 2001 .

[2]  William L. Haberman,et al.  AN EXPERIMENTAL INVESTIGATION OF THE DRAG AND SHAPE OF AIR BUBBLES RISING IN VARIOUS LIQUIDS , 1953 .

[3]  F. Fahy,et al.  Mechanics of flow-induced sound and vibration , 1989 .

[4]  M. L. Billet,et al.  Freestream Nuclei and Traveling-Bubble Cavitation , 1992 .

[5]  K. Farrell,et al.  Eulerian/Lagrangian Analysis for the Prediction of Cavitation Inception , 2003 .

[6]  F. Menter ZONAL TWO EQUATION k-w TURBULENCE MODELS FOR AERODYNAMIC FLOWS , 1993 .

[7]  W. Jones,et al.  The calculation of low-Reynolds-number phenomena with a two-equation model of turbulence , 1973 .

[8]  M. Plesset The Dynamics of Cavitation Bubbles , 1949 .

[9]  Hugh W. Coleman,et al.  Comprehensive Approach to Verification and Validation of CFD Simulations—Part 2: Application for Rans Simulation of a Cargo/Container Ship , 2001 .

[10]  J. Riley,et al.  Equation of motion for a small rigid sphere in a nonuniform flow , 1983 .

[11]  A. Gosman,et al.  Solution of the implicitly discretised reacting flow equations by operator-splitting , 1986 .

[12]  Frederick Stern,et al.  Computational fluid dynamics of four-quadrant marine-propulsor flow , 1999 .

[13]  L. Crum,et al.  Acoustic Cavitation , 1982 .

[14]  Numerical Simulation of Bubble Dynamics in a Vortex Flow Using Navier-Stokes Computations and Moving Chimera Grid Scheme , 2001 .

[15]  C. Brennen,et al.  Observations and scaling of travelling bubble cavitation , 1995, Journal of Fluid Mechanics.

[16]  Frederick Stern,et al.  GENERAL-PURPOSE PARALLEL UNSTEADY RANS SHIP HYDRODYNAMICS CODE: CFDSHIP-IOWA , 2003 .

[17]  D. Wilcox Reassessment of the scale-determining equation for advanced turbulence models , 1988 .