Session: 06-15-01 Unsteady Hydrodynamics, Vibrations, Acoustics and Propulsion - I

Submission Number: 176769

Hydrodynamic Characteristics of a Marine Toroidal Propeller in Comparison With a Conventional Propeller 

The toroidal propeller (TP) has recently emerged as a novel propulsion concept characterized by its continuous ring-like blade connection that eliminates the conventional blade tip. This unique geometry has shown potential advantages in suppressing tip vortex formation, mitigating cavitation, and improving hydrodynamic efficiency. However, quantitative evaluations of its performance under open-water conditions remain limited compared with traditional propellers.

In this study, a toroidal propeller was systematically designed based on the mathematical representation of a conventional propeller (CP) to ensure geometric similarity and allow a direct comparison of hydrodynamic performance. Numerical simulations were conducted using STAR-CCM+, applying the Multiple Reference Frame (MRF) approach in conjunction with the Arbitrary Mesh Interface (AMI) technique to model the steady flow field around rotating blades. The analysis focused on evaluating thrust, torque, and efficiency characteristics across a range of advance coefficients.

The computational results reveal several distinctive hydrodynamic features of the toroidal propeller compared with the conventional design. The continuous ring structure of the TP effectively redistributes the circulation near the blade tips, leading to a significant reduction in tip vortex intensity and associated pressure fluctuations. This vortex suppression contributes to a more uniform wake flow and a lower likelihood of cavitation inception. Moreover, the TP demonstrates a slightly higher propulsive efficiency in the moderate advance coefficient range, attributed to reduced induced losses and improved load distribution along the span.

These findings provide valuable insights into the fundamental mechanisms governing the hydrodynamic performance of toroidal propellers. The results suggest that the toroidal configuration can achieve comparable or even superior propulsive performance while offering additional benefits in terms of noise and cavitation reduction. Consequently, the TP represents a promising alternative for next-generation marine propulsion systems, particularly in applications where quiet operation and vibration suppression are critical.

 

Presenting Author: Yuehui Shu Hiroshima University

Presenting Author Biography: PhD Student
Graduate School of Advanced Science and Engineering, Hiroshima University, JAPAN

Authors:

Yuehui Shu Hiroshima University
Hidemi Mutsuda Hiroshima University
Takuji Nakashima Hiroshima University
Shogo Nakada Hiroshima University
Motomichi Yamamoto Hiroshima University
Hiroaki Aizawa Miraisozo Investments Inc.
Yukio Watanabe National Institute of Technology, Toba College