CAJ | 학술논문

通过对三角翼上漩涡破裂形态及涡破裂过程的流态变化的分析,可以得到以下结论.在三角翼上,除了通常知道的螺旋破裂核泡状破裂之外,还有双螺旋、涡丝以及蛙跳另外3种破裂形态.涡破裂是一个非定常过程,在机翼形状、迎角及来流条件不变的情况下,通常可以看到涡破裂形态的变化,即从螺旋破裂逐渐转化成泡状破裂又返回到螺旋破裂的过程.泡状破裂可以认为是螺旋破裂的一种特殊阶段.它与螺旋破裂并没有本质上的区别.从形态上看,泡状破裂中会出现涡核分叉,涡核中分离出一些带有涡量的流体微团,但总有一根涡丝(一部分涡核),自始至终存在,它或者表现成螺旋形态,或者由于自身的诱导形成了较复杂的缠绕形态.
통과대삼각익상선와파렬형태급와파렬과정적류태변화적분석,가이득도이하결론.재삼각익상,제료통상지도적라선파렬핵포상파렬지외,환유쌍라선、와사이급와도령외3충파렬형태.와파렬시일개비정상과정,재궤익형상、영각급래류조건불변적정황하,통상가이간도와파렬형태적변화,즉종라선파렬축점전화성포상파렬우반회도라선파렬적과정.포상파렬가이인위시라선파렬적일충특수계단.타여라선파렬병몰유본질상적구별.종형태상간,포상파렬중회출현와핵분차,와핵중분리출일사대유와량적류체미단,단총유일근와사(일부분와핵),자시지종존재,타혹자표현성라선형태,혹자유우자신적유도형성료교복잡적전요형태.
Visualization test is performed at the water channel of BUAA. The vortex core is visualized by dye injection from a small tube located upstream the apex of a delta wing. The test results are recorded by a video camera connected to a computer and processed by Photoshop\+ software. The test shows new findings in the following respects:(1) Besides the well known spiral and bubble forms of vortex breakdown, there are 3 other forms of vortex breakdown over delta wing found in the test. They are the frog-jump form, the double spiral form and the filiform spiral form.(2) It has also been found that there is a transition from the spiral form to the bubble form and then back to the spiral form in the test. Therefore it shows that the spiral form vortex breakdown over delta wing is often observed.(3) In a certain sense it can be said that the bubble form of vortex breakdown is a special case of the spiral form type. There is no essential difference between them. For the bubble form of vortex breakdown, there are branches of the vortex core and many elements carrying vorticity separated from the vortex core. However, there is at least one vortex filament that forms a spiral or a complex warping shape.