To reduce the load difference between the inside and outside propeller of a four-propeller ship, a differenti-ated theoretical design method on the propeller was developed. First, the initialized design on the inside and outside propeller was performed, the total thrust deduction fraction of the integrated ship and propeller and the wake fraction of the inside and outside propeller were predicted by applying CFD technology and the equal-thrust method;second, by combining the theoretical design method and panel method on the propeller, a differentiated theoretical design sys-tem on the propeller was established;and finally, taking a four-propeller ship as an example, the method in this pa-per was applied to perform a differentiated design on the inside and outside propeller at the maximum speed;in addi-tion, the design effects at different navigation speeds were analyzed. The results show that the total thrust meets the design requirements, the load difference decreases from 11. 9% at the preliminary design to 0. 61%; moreover, the load difference decreases from 13. 8% and 13. 3% at the preliminary design to 5. 65% and 3. 68%, respectively, for navigation speeds of 18kn and 25kn. The method presented in this paper can decrease the load difference between in-side and outside propellers, which provides a new idea for the design of four-propeller ships.%为了减小四桨船舶内外桨的负荷差,本文建立了一套螺旋桨差异化理论设计方法.基于螺旋桨的理论设计方法进行了内外桨的初始化设计,并采用CFD技术和等推力法,预报船桨一体的总推力减额分数和内外桨的伴流分数.结合螺旋桨理论设计方法和面元法,形成了一套螺旋桨差异化理论设计系统.并以某四桨船舶方案为例,在最大航速工况下,应用本文的方法开展内外桨的差异化设计,并对不同航速下的螺旋桨差异化设计效果进行分析.研究表明:在最大设计航速下,内外差异化设计桨的总推力满足设计要求,负荷差由初步设计时的11.9%减小为0.61%左右,而且在18节和25节航速下的负荷差也分别由初步设计时的13.8%与13.3%减少到5.65%与3.68%.应用本文方法可有效地减小内外桨的负荷差,为四桨船舶螺旋桨设计提供了新思路.
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