Numerical investigation of internal flow characteristics in an azimuth waterjet propulsion at different ship speeds

作者：Peng Yan, Ruizhi Zhang, Kunyu Meng, Hao Geng, Jiajian Zhou, Yan Zhang, Jianping Chen · 发表于：Applied Ocean Research · 年份：2025 · DOI：10.1016/j.apor.2024.104406 · 被引用次数：6 · 研究领域：Cavitation Phenomena in Pumps、Ship Hydrodynamics and Maneuverability、Fluid Dynamics Simulations and Interactions

Azimuth waterjet propulsion is a special kind of waterjet propulsion, which is installed flush with the bottom of hull and 360 deg steerable. It is widely used in ships to broaden navigation range, enhance adaptability in shallow water area and improve maneuverability. In this study, an azimuth waterjet propulsion is investigated by numerical simulations. The predicted bollard thrust is in good agreement with experimental data and the accuracy of numerical method is validated. The computational fluid dynamics (CFD) simulation is performed at several ship speeds to study its effect on performance and internal flow field. The local Euler head distribution (LEHD) is used to evaluate the pattern of energy growth on different constant stream surfaces of impeller. The concept of entropy generation rate is introduced to measure the intensity and location of loss generation inside azimuth waterjet propulsion. The loss generations of different regions and its variations at different ship speeds are presented, the impeller and diffuser domain are found to make dominant contribution to loss generation. Four main sources of loss in diffuser domain are identified, and the flow mechanism responsible for the loss generation is analyzed in detail to give guidance for further performance improvement of azimuth waterjet propulsion. The main reason for the abrupt decrease in efficiency and thrust at high ship speed is also illustrated and clarified.