基于响应面的渔船球鼻艏参数分析及多航速自动优化

Parameter investigation and multi-speed automatic optimization of fishing vessel's bulb bow based on the response surface

远洋金枪鱼围网渔船是一种中、高速的作业型船舶,加装球鼻艏并进行优化可以有效降低其兴波阻力。通过一种改造型值的球鼻艏变换方法,由球鼻艏的长度、宽度、高度及尖点高度参数直接生成用于CFD计算的船体型值,可以快速探讨球鼻艏对兴波阻力的影响。兴波阻力的计算采用Rankine源势流理论,运用试验设计方法生成球鼻艏参数对兴波阻力影响的响应面模型。该模型表明,各参数的影响是复杂且耦合的,难以呈现单调的规律性,且在不同航速下其影响规律也有差异。优化球鼻艏的过程选用结合响应面的快速优化方法,通过优化,发现传统的对单一设计航速的优化可能会出现在较低的服务航速下阻力增加的情形,而采用多个航速的阻力优化方法则在设计航速与服务航速下同时具有减阻节能效果。

The pelagic tuna purse seiner is a medium-high speed fishery vessel. To reduce its wave resistance, an optimized bulbous bow is usually installed. In order to effectively investigate the bulb bow effect on the wave resistance, a bulb bow transformation method is developed in this paper, through which the bulb bow offsets are transformed into length, breadth, height, and fore-point height parameters and directly used in CFD calculation. The wave resistance is then solved with the Rankine source panel method. Using the method of experimental design, a response surface model of bulb bow parameter effect on wave resistance is generated. The response surface model indicates that the influences are rather complex, coupled and irregular, and the exact rules differ with speed. Finally, a fast optimization method based on the response surface is applied into the bulb bow optimization, and it is noticed that the optimal solution for the design speed could yield worse resistance performance under service speed, while the multi-speed optimization method is more effective for the resistance reduction and energy saving under both design speed and service speed.