Integration of a Viscous Flow RANS Solver with an Unsteady Propulsor Force Code

Abstract : The unsteady propeller force code PUF-2.1 has been coupled with DTNS - a viscous RANS flow solver. The effects of the propeller are modeled via a spatially varying time averaged body force distribution incorporated in the RANS equations. Simple test cases are presented showing that the code properly handles an open water flow as well as a circumferentially varying inflow. Differences between the new code and its steady counterpart are highlighted, both from the standpoint of the code implementation as well as the calculated physical results. The work is easily extendable to the parallel version of UNCLE and maneuvering calculations performed as part of the DOD Challenge Program when the unsteady forces and propulsor effect are obtained from PUF as a precursor to the full RANS calculations of the entire boat with propulsor.