Cavitating Flow Calculations for the E779A Propeller in Open Water and Behind Conditions- Code comparison and solution validation

As part of the Cooperative Research Ships SHARCS project, calculations of the E779A propeller in open water and in a cavitation tunnel behind wake generating plates have been performed by ten different institutions using eight different flow codes. Both full RANS and RANS-BEM coupled approaches have been used to predict wetted and cavitating flows. Propeller performance characteristics, pressure distributions, limiting-streamlines and cavitation volumes have been analyzed. Cavitation patterns have been compared with photographs. In addition, pressure fluctuations at the cavitation tunnel walls and at some hydrophones have been computed and compared against available experimental data. For loading and cavitation extents, there is good agreement among the different calculations. Compared with measurements, the predicted cavity extents are good but the propeller thrust for the behind condition was uniformly under-predicted. The overall agreement is an improvement over earlier studies using the same data set. The pressure fluctuations predicted by half the participants were in reasonable agreement with measurements, but the remaining calculations predicted pressure levels a factor of four or five too high.