Full-scale simulation and analysis of self-propulsion performance of CRP-propelled high speed underwater vehicles

Objectives  In order to numerically predict the self-propulsion factors of high speed underwater vehicles equipped with Contra-Rotating Propellers (CRP), Methods  RANS modeling approaches are developed for vehicle resistance, self-propulsion and CRP open-water simulation. In terms of resistance and open-water performance, the modeling accuracy are validated by comparisons with model experiments. Based on quasi-steady and unsteady simulations of a high speed underwater vehicle at full scale, the self-propulsion factors are analyzed and compared. Results  The comparison of the numerical and experimental results at the model scale indicates that the simulation error margin of vehicle resistance is less than 3%, while those of CRP thrust and torque are less than 2% and 4% respectively. The numerically simulated full-scale resistance is 3% lower than that predicted by the model test data. The self-propulsion factors yielded from full-scale RANS simulations are all reasonable in magnitude. The self-propulsion factors yielded from the quasi-steady and unsteady models differ by less than 2%, indicating that the quasi-steady model is an economical choice for engineering applications. Conclusions  The present modeling approaches are capable of supplying self-propulsion factors for CRP design with reasonable accuracy, and are expected to enhance design accuracy and work efficiency.