船舶螺旋桨空泡数值预报及参数影响分析

发布时间：2019-04-26 23:34

【摘要】：随着科学技术的发展,各种新船型、高性能船相继出现,现代船舶不断的向大型化、高速化方向发展,螺旋桨负荷不断加重,往往难以避免在桨叶上出现空泡。螺旋桨空泡会对螺旋桨性能造成影响,可能会产生空泡剥蚀并对桨叶造成破坏,同时螺旋桨空泡还会引起船体尾部振动和噪声等问题。本文采用基于扰动速度势面元法建立了在均流/非均匀流条件下螺旋桨桨叶片空泡数值预报方法,研究分析了网格数、Kutta条件处理等对计算结果的影响,利用较为完整的三维空泡流动边界条件以及通过空泡末端厚度快速移动空泡末端网格取代传统非线性Newton-Raphson迭代来确定空泡区域方法,有效地提高了计算的稳定性和收敛性。针对本文所建立的螺旋桨空泡数值预报方法,进行了较为充分的数值验证。在均流条件下,对5600TEU集装箱船螺旋桨、PC456标准螺旋桨以及INSEAN水池E779A螺旋桨空泡进行了数值计算和分析;在非均匀流条件下,对5600TEU螺旋桨非定常空泡进行了计算,分析了空泡区域大小及空泡随角度变化特性等,数值计算结果均与模型试验结果有较好的吻合,验证结果表明本文方法在船舶螺旋桨空泡的数值定量预报上具有可行性和实用性。在此基础上,利用本文方法重点分析了螺旋桨侧斜、纵倾分布以及叶剖面等设计参数对空泡性能的影响,计算结果表明,加大侧斜,可以减小桨叶表面空泡面积,对于非定常流动表现更为明显;无论定常还是非定常流动,桨叶剖面设计对螺旋桨空泡性能影响很大,抗空化叶剖面的应用,可以大幅度地减小空泡面积,提高抗空化能力;采用非线性纵倾,在桨叶梢部可形成局部向压力面弯曲的形式,可以改善梢部的压力分布,减少梢部空泡面积,结合这种分布形式同样可以抑制梢涡,因而优化梢部纵倾分布也是减少空泡,降低螺旋桨空泡诱导脉动压力的一种措施。本文的研究分析工作,为空泡螺旋桨的优化设计提供了基础,同时也表明本文方法可以在螺旋桨优化设计过程中用来评估分析参数优化对空泡性能的影响。
[Abstract]:With the development of science and technology, all kinds of new ship types and high-performance ships appear one after another. The modern ships are developing to large-scale and high-speed, and the propeller load is increasing constantly. It is difficult to avoid the cavitation on the propeller blades. The cavitation of propeller will affect the performance of propeller, which may cause cavitation denudation and damage to the blade. At the same time, the cavitation of propeller will also cause vibration and noise at the tail of the ship. In this paper, the numerical prediction method of propeller blade cavitation under the condition of uniform / non-uniform flow is established based on the perturbation velocity potential surface element method. The effects of grid number and Kutta condition treatment on the calculated results are studied and analyzed. The computational stability and convergence are improved by using the relatively complete three-dimensional bubble flow boundary conditions and replacing the traditional nonlinear Newton-Raphson iteration with the fast moving bubble end mesh at the end of the bubble. The results show that the computational stability and convergence of the method can be improved effectively by using the three-dimensional bubble flow boundary conditions. In this paper, the numerical prediction method of propeller cavitation is fully verified. Under the condition of current sharing, the numerical calculation and analysis of 5600TEU container ship propeller, PC456 standard propeller and INSEAN pool E779A propeller cavitation are carried out. Under the condition of non-uniform flow, the unsteady cavitation of 5600TEU propeller is calculated, and the size of cavitation region and the variation of cavitation with angle are analyzed. The numerical results are in good agreement with the results of model test, and the numerical results are in good agreement with the experimental results. The verification results show that the proposed method is feasible and practical in the numerical prediction of propeller cavitation. On this basis, the effects of the design parameters such as propeller slant, pitch distribution and blade profile on the cavitation performance are analyzed. The results show that the cavitation area on the blade surface can be reduced by increasing the slant, and the influence of the design parameters such as the pitch distribution and the blade profile on the cavitation performance is analyzed in detail. The performance of unsteady flow is more obvious. No matter the steady or unsteady flow, the blade profile design has a great influence on the cavitation performance of propeller. The application of anti-cavitation blade profile can greatly reduce the cavitation area and improve the cavitation resistance ability. By adopting non-linear longitudinal inclination, the form of local bending of pressure surface can be formed at the tip of the blade, which can improve the pressure distribution of the tip and reduce the bubble area of the tip. Combined with this distribution form, the vortex of the tip can also be suppressed. Therefore, optimizing the tip tilt distribution is also a measure to reduce the cavitation and reduce the pulsatile pressure induced by the propeller cavitation. The research and analysis work in this paper provides a basis for the optimal design of cavitation propeller, and also shows that this method can be used to evaluate the effect of optimization of parameters on cavitation performance in the process of optimization design of propeller.
【学位授予单位】：中国舰船研究院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U664.33;U661.1

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