Recent developments in Computational Fluid Dynamics (CFD) and high-performance computer hardware have made it possible to design Energy Saving Devices (ESDs) using numerical methods. The present work investigates the influence of rudder bulb diameter, thrust fin; span, chord length and angle of attack on propulsive efficiency. In order to increase computational efficiency, a hypothesis was developed and a quick estimate method for design parameters and the optimization procedure. Bare hull resistance, propeller open water performance and interaction of hull-propeller-rudder simulations were carried out using CFD code to solve Reynolds Averaged Navier-Stokes (RANS) equations. A validation study shows a good agreement between the CFD and experimental data. Model tests were carried out using optimum parameters for rudder bulb and rudder attached thrust fins. Comparison of the propulsive efficiency between the ship with the conventional rudder and ship with the optimized rudder-bulb-fin device was done. The model test predicted energy gains of 2.18% compared to 2.63% gains predicted by the CFD method. This study would be useful during design and optimization of rudder-bulb-fin.

计算流体动力学 (CFD) 和高性能计算机硬件的最新发展使得使用数值方法设计节能设备 (ESD) 成为可能。目前的工作研究了舵球直径、推力鳍的影响；跨度、弦长和攻角对推进效率的影响。为了提高计算效率，开发了一个假设以及一种设计参数和优化程序的快速估计方法。裸船体阻力、螺旋桨开放水域性能和船体-螺旋桨-舵模拟的相互作用使用 CFD 代码进行，以求解雷诺平均纳维-斯托克斯 (RANS) 方程。验证研究表明 CFD 和实验数据之间具有良好的一致性。使用舵球和舵附推力翼的最佳参数进行模型试验。对采用常规舵的船舶与采用优化舵-球-鳍装置的船舶的推进效率进行了比较。模型测试预测的能量增益为 2.18%，而 CFD 方法预测的能量增益为 2.63%。这项研究将有助于舵球鳍的设计和优化。