HYDRODYNAMIC MODELLING OF UNSTEADY INTERACTIONS AMONG PODDED PROPULSOR COMPONENTS

A theoretical methodology for the hydrodynamic analysis of a podded propeller is presented. The aim is to provide a computational tool to investigate the unsteady flowfield generated by the mutual interactions between rotating and fixed (passive) components. The methodology is based on a boundary integral formulation for the velocity potential that is valid for inviscid flows around multi-body configurations in arbitrary motion. A wake alignment technique is used to describe the propeller-induced trailing vorticity and a wake/body inpingement model is proposed to study the interactions between the propeller wake and the strut in a pulling-type pod configuration. An efficient numerical solution procedure based on a domain decomposition technique is derived. Numerical results are presented to validate the wake/body inpingement model and to demonstrate the capability of the proposed methodology to describe some relevant features of podded propeller flows.