Prediction of ship power and speed performance based on RANS method

Abstract

This paper adopts virtual tank experimental technology to study ship rapidity performance. Based on RANS method, a new method is put forward to predict the speed and power performance of full scale ship. The open water performance of propeller model, the resistance performance of ship model and the self-propulsion performance of ship model are numerically calculated. Through the analysis of rapidity numerical results of fishing ship and the change law of wake flow field, some conclusions can be drawn. The numerical prediction accuracy of propeller open water efficiency has a direct influence on total thrust efficiency. The interference between hull, propeller and rudder leads to the formation of a lower pressure zone on stern hull surface and rudder surface. The axial velocity and radial velocity are affected by the interference between the flow of hull stern and propeller, the absolute value of axial velocity on blade leaf is smaller than that on blade back, and the radial velocity induces vortices on the blade tip of the propeller. The increase of propeller rotation speed nearly has no effect on the free surface wave pattern. The prediction results deviations of full scale ship speed and propeller rotation speed between RANS method and EFD method are 0.04 kn and 0.4 r/min, and therefore they are negligible. The proposed method can provide reference for engineering application.