Study on Hydrodynamic Coefficients and Maneuverability of a Submerged Body by Applying CFD Method

The present study focuses on the developement of Computational Fluid Dynamics (CFD) methods to calculate the hydradynanimc coefficients of DARPA SUBOFF model and analyze its maneuverability including directional stability and turning ability. The experiments of DARPA SUBOFF model were performed in the David Taylor Model Basin using the planar motion mechanism (PMM) to determine the stability and control characteristics of the model. These experimental data served as a bentch mark for CFD validations, which was identified as the Defense Advanced Research Projects (DARPA) SUBOFF project. In the present study, the CFD software ANSYS FLUENT is applied to simulate the maneuver motions of DARPA SUBOFF model, including motions of oblique towing test, rotating arm test, rudder force test, constant accelerating test and PMM test, and the corresponding hydradynanimc forces and hydradynanimc coefficients can be obtained. With these hydradynanimc coefficients and equations of horizontal maneuvering motions, the maneuverability of DARPA SUBOFF model can finally be analyzed. The CFD simulation results are compared with those of experimens. Similar to the analysis results from experiments, CFD simulation results also indicate that all configurations of DARPA SUBOFF model are directional unstable, which can be improved by adding appendages.Comparing with the simulation results of PMM test, that of oblique towing test, rotating arm test, and constant accelerating test are more reliable and more accurate.