Numerical Prediction of the Performance of Podded Propulsors and Ducted Propellers Available to Purchase

A general numerical method to predict the hydrodynamic performance of podded propulsors and ducted propellers is presented. This method couples a Vortex-Lattice Method (VLM) and a Finite Volume Method (FVM) based Euler solver to account for the interactions between the propeller blades and a duct or pod with strut. The VLM is applied to the each blade inside the duct or on the pod, and solves for the potential flow in the vicinity of the blade and predicts the pressures, forces, moments and cavity patterns. The FVM is applied to the whole fluid domain including the duct or pod. The Euler equations are solved with the pressure difference across the blades being converted into body force terms and the duct or pod being modeled as solid wall boundaries. The “effective wake” in front of each propeller plane is evaluated, and the VLM solves for the flow on the blades subject to this “effective wake”. Using an iterative procedure, the interaction between appendages (pod, strut and duct) and propeller is captured. The method is applied to two types of podded propulsors and a ducted propeller and the results are compared to those measured in experiments.