Numerical analysis of self-propulsion flow characteristics in model scale

Abstract

In this paper, a detailed numerical analysis of global, and local flow characteristics of a self-propelled KCS model is presented. Global flow characteristics are integral values such as thrust and torque, while the local flow characteristics are represented by the velocity components. Three different numerical propeller representations are considered: fully discretized propeller, actuator disc model which models the thrust effect on the fluid flow only, and actuator disc model that models both thrust and torque effects. Verification is performed using method based on Richardson extrapolation, and the approach is validated with publicly available experimental data, both for global and local flow characteristics. A procedure for accurate prediction of global and local self-propulsion characteristics using a combination of actuator disc and discretized propeller methods is presented. The hybrid procedure was proved to provide a good agreement of global flow characteristics with experimental data. The fully discretized propeller model using overset grid showed good accuracy of predicting local flow characteristics, observed by comparing axial and in-plane velocity components behind the working propeller.