摘要
梢涡空化是船用螺旋桨上最早发生的空化类型之一,其一旦发生会显著增强舰船水下噪声水平.因此,随着现代舰船对航速和声隐身性的要求不断提高,对于与舰船临界航速密切相关的螺旋桨梢涡空化初生的精准预报需求也变得日益迫切.而现阶段常用的单相最小压力系数法和两相空化模型法不仅无法充分考虑水中气核效应,还具有明显的网格依赖性,难以对螺旋桨梢涡的初生空化数进行精准预报.为弥补现有预报方法的不足,本研究在考虑气核效应的流场模拟方法基础上,建立了基于趋势突变检验的螺旋桨梢涡初生空化数的预报方法.首先以由螺旋桨桨叶简化而来的椭圆翼为研究对象针对该方法中空化泡判定标准和初始气核数量两个主观因素进行敏感性分析,较为系统验证了该预报方法具有优异的鲁棒性.并在此基础上,初步探究了来流速度对梢涡卷吸捕获气核能力的影响.研究表明,在空化初生工况下,来流速度越大使得气核就越难以被梢涡流场捕获后生长成为空化泡.最后进一步地将该方法应用于螺旋桨的梢涡空化初生的预报研究中.结果表明,相较于传统最小压力系数法,本方法精度能提高80%以上,优势明显.
Tip vortex cavitation is one of the earliest cavitation types on marine propellers and once it occurs,it will significantly enhance the underwater noise level of ships.Therefore,with the increasing requirements of modern ships for speed and acoustic stealth performance,the demand for accurate prediction of propeller tip vortex cavitation inception,which is closely related to the critical speed of ships,has become increasingly urgent.However,the commonly used single-phase minimum pressure coefficient method and two-phase cavitation model method at this stage not only cannot fully consider the nuclei effect in the water,but also have obvious mesh dependence,which makes it difficult to accurately predict the tip vortex cavitation inception number of the propeller.So as to make up for the shortcomings of the existing prediction methods,a prediction method for the propeller tip vortex cavitation inception number based on the trend mutation test is established on the basis of the flow field simulation method considering the nuclei effect.Firstly,the elliptical wing simplified from the propeller blade is used as the research object to conduct sensitivity analysis on two subjective factors,namely,the judgement criteria of cavitation bubbles and the number of initial nuclei,to systematically verify the excellent robustness of this prediction method.Based on this,the influence of incoming flow velocity on the ability of tip vortex to capture nuclei is preliminarily explored.Research indicates that under cavitation inception conditions,a higher incoming flow velocity makes it more difficult for the nuclei to be captured by the tip vortex and grow into a cavitation bubble.Finally,the method is further applied to the prediction study of propeller tip vortex cavitation inception,and the results show that the accuracy of this method can be improved by more than 80%compared with the traditional minimum pressure coefficient method,which has obvious advantages.
作者
韦喜忠
王永帅
陈奕宏
季斌
Wei Xizhong;Wang Yongshuai;Chen Yihong;Ji Bin(China Ship Scientific Research Center,Wuxi 214082,Jiangsu,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China)
出处
《力学学报》
北大核心
2025年第3期605-615,共11页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(52479085).
关键词
数值模拟
气泡动力学
突变检验
梢涡空化初生
螺旋桨
numerical simulation
bubble dynamics
mutation test
tip vortex cavitation inception
marine propeller
作者简介
通讯作者:季斌,教授,主要研究方向为船舶推进器空化水动力学.E-mail:jibin@whu.edu.cn。
