The effects of domain division types on the performance prediction of a rim-driven thruster

Abstract

The rim-driven thruster (RDT) is an innovative propulsion thruster. The rotating subdomain can contain different assemblies with different domain division types (DDT). This paper tried to figure out the effects of DDT on the performance of RDT. This paper uses the Delayed Detached Eddy Simulation (DDES) turbulence model to conduct the simulations. Three DDTs are carefully analyzed to understand their effects on predictive performance. The convergence analysis is performed by taking a typical method: Grid Convergence Index (GCI). Some theoretical results and the experimental hydrodynamics of a popular combination of Ka 4–70 and MARIN 19 A are used to validate the numerical method. The numerical results demonstrate that the computational efficiency is influenced by the cell number on the interfaces between two subdomains and an inherent characteristic of DDT. Moreover, the torques acting on rim surfaces are closely accounting for the gap flow. Moreover, regarding the morphology and variables of the vortex system, the third type of DDT enhances vortices presenting in the hub region and vortex-instability region. Although the present analysis is performed for an RDT, the findings should be generally applicable for other RDT designs with similar structures and operational conditions.