船舶力学
船舶力學
선박역학
Journal of Ship Mechanics
2015年
11期
1304-1311
,共8页
赵宇%王国玉%黄彪%刘雷鸣
趙宇%王國玉%黃彪%劉雷鳴
조우%왕국옥%황표%류뢰명
叶顶间隙涡%空化%非定常%图像处理%涡空化模型
葉頂間隙渦%空化%非定常%圖像處理%渦空化模型
협정간극와%공화%비정상%도상처리%와공화모형
tip leakage vortex%cavitation%unsteadiness%imagine processing%vortex cavitation model
采用试验的方法研究了不同空化数下水翼叶顶间隙区域漩涡空化流动的发展变化。试验在闭式空化水洞中进行,采用高速全流场显示技术对空化流场进行观测,并采用图像处理技术对试验结果进行处理,提出空化涡模型,阐述了涡空化的发展规律。研究结果表明:随着空化数的降低,叶顶间隙漩涡空化的发展主要经历如下三个阶段:(I)泄露涡内部空化初生阶段:在水翼中部附近产生游离状空化,向下游运动并迅速溃灭消失。(II)叶顶间隙内部附着空化发展阶段:涡空化逐渐发展并向水翼尾缘延伸,空化涡带呈螺旋状非轴对称旋转;叶顶位置压力面中部附近开始出现片状附着型空化,并体现出强烈的非定常特性。(III)射流剪切层内部空化形成阶段:涡空化延伸至水翼下游;叶顶附着空化充分发展,充满间隙并形成射流剪切层空化,和空化涡带共同形成三角状空化结构。
採用試驗的方法研究瞭不同空化數下水翼葉頂間隙區域漩渦空化流動的髮展變化。試驗在閉式空化水洞中進行,採用高速全流場顯示技術對空化流場進行觀測,併採用圖像處理技術對試驗結果進行處理,提齣空化渦模型,闡述瞭渦空化的髮展規律。研究結果錶明:隨著空化數的降低,葉頂間隙漩渦空化的髮展主要經歷如下三箇階段:(I)洩露渦內部空化初生階段:在水翼中部附近產生遊離狀空化,嚮下遊運動併迅速潰滅消失。(II)葉頂間隙內部附著空化髮展階段:渦空化逐漸髮展併嚮水翼尾緣延伸,空化渦帶呈螺鏇狀非軸對稱鏇轉;葉頂位置壓力麵中部附近開始齣現片狀附著型空化,併體現齣彊烈的非定常特性。(III)射流剪切層內部空化形成階段:渦空化延伸至水翼下遊;葉頂附著空化充分髮展,充滿間隙併形成射流剪切層空化,和空化渦帶共同形成三角狀空化結構。
채용시험적방법연구료불동공화수하수익협정간극구역선와공화류동적발전변화。시험재폐식공화수동중진행,채용고속전류장현시기술대공화류장진행관측,병채용도상처리기술대시험결과진행처리,제출공화와모형,천술료와공화적발전규률。연구결과표명:수착공화수적강저,협정간극선와공화적발전주요경력여하삼개계단:(I)설로와내부공화초생계단:재수익중부부근산생유리상공화,향하유운동병신속궤멸소실。(II)협정간극내부부착공화발전계단:와공화축점발전병향수익미연연신,공화와대정라선상비축대칭선전;협정위치압력면중부부근개시출현편상부착형공화,병체현출강렬적비정상특성。(III)사류전절층내부공화형성계단:와공화연신지수익하유;협정부착공화충분발전,충만간극병형성사류전절층공화,화공화와대공동형성삼각상공화결구。
Experimental investigations of unsteady cavitating flows in a hydrofoil tip leakage region are con-ducted to highlight the development of cavitation with various cavitation numbers. The experiments were taken in a closed cavitation tunnel, during which high speed camera was used to capture the cavitation patterns. Image processing was also used to get further analysis. Besides, cavitating vortex model is proposed to de-scribe the development of vortex cavitation. Based on the results, three stages can be defined as the de-crease of cavitation number. In the first stage, called the inception of tip leakage vortex cavitation, a rapid onset-growth-collapse process of the vortex cavitation can be observed near the middle and rear parts of the hydrofoil. In the second stage, called the development of attached leakage cavitation, aforementioned vortex cavitation develops gradually with non-axisymmetric and twists rotation, and attached sheet cavitation inside the gap with strong unsteadiness can be observed neat the middle part of the hydrofoil. In the last stage, called formation and development of jet shear layer cavitation, vortex cavitation stretches towards downstream, and aforementioned attached cavitation develops beyond the gap and combines with the vortex cavitation, to form the triangle cavitating region.