西北工业大学学报
西北工業大學學報
서북공업대학학보
JOURNAL OF NORTHWESTERN POLYTECHNICAL UNIVERSITY
2014年
5期
667-674
,共8页
张乐%周洲%李盈盈%甘文彪%许晓平
張樂%週洲%李盈盈%甘文彪%許曉平
장악%주주%리영영%감문표%허효평
飞翼无人机%保形设计%非对称尾喷管%圆矩形%面积比%流场特性%数值模拟
飛翼無人機%保形設計%非對稱尾噴管%圓矩形%麵積比%流場特性%數值模擬
비익무인궤%보형설계%비대칭미분관%원구형%면적비%류장특성%수치모의
基于飞翼布局无人机隐身与保形设计要求,设计了不同面积比的四边形和圆矩形2类非对称尾喷管,并利用数值模拟方法对无人机内外流耦合流动进行了计算分析,获得了无人机全机纵向气动性能与尾喷管三维流场特性。结果表明:保形非对称尾喷管可用于改善飞翼无人机的纵向力矩特性,且圆矩形喷管升阻特性和力矩特性比四边形喷管更优;收敛型喷管(面积比Ar≤1?0)无法在设计点(发动机喷口)而是在尾喷管出口处形成喉道,并在喉道处形成强激波阻滞喷流排出;随着面积比增大,轴向推力系数先增大后减小,存在最佳面积比,而且相同面积比下圆矩形喷管比四边形喷管推力性能更佳;扩张型喷管内激波的强度随着面积比增大变得更强,圆矩形喷管结尾处的激波角比四边形喷管小,喷流阻滞作用更小;对于此类飞翼布局无人机采用面积比为1?2~1?4的圆矩形喷管,将获得较理想的气动性能。
基于飛翼佈跼無人機隱身與保形設計要求,設計瞭不同麵積比的四邊形和圓矩形2類非對稱尾噴管,併利用數值模擬方法對無人機內外流耦閤流動進行瞭計算分析,穫得瞭無人機全機縱嚮氣動性能與尾噴管三維流場特性。結果錶明:保形非對稱尾噴管可用于改善飛翼無人機的縱嚮力矩特性,且圓矩形噴管升阻特性和力矩特性比四邊形噴管更優;收斂型噴管(麵積比Ar≤1?0)無法在設計點(髮動機噴口)而是在尾噴管齣口處形成喉道,併在喉道處形成彊激波阻滯噴流排齣;隨著麵積比增大,軸嚮推力繫數先增大後減小,存在最佳麵積比,而且相同麵積比下圓矩形噴管比四邊形噴管推力性能更佳;擴張型噴管內激波的彊度隨著麵積比增大變得更彊,圓矩形噴管結尾處的激波角比四邊形噴管小,噴流阻滯作用更小;對于此類飛翼佈跼無人機採用麵積比為1?2~1?4的圓矩形噴管,將穫得較理想的氣動性能。
기우비익포국무인궤은신여보형설계요구,설계료불동면적비적사변형화원구형2류비대칭미분관,병이용수치모의방법대무인궤내외류우합류동진행료계산분석,획득료무인궤전궤종향기동성능여미분관삼유류장특성。결과표명:보형비대칭미분관가용우개선비익무인궤적종향력구특성,차원구형분관승조특성화력구특성비사변형분관경우;수렴형분관(면적비Ar≤1?0)무법재설계점(발동궤분구)이시재미분관출구처형성후도,병재후도처형성강격파조체분류배출;수착면적비증대,축향추력계수선증대후감소,존재최가면적비,이차상동면적비하원구형분관비사변형분관추력성능경가;확장형분관내격파적강도수착면적비증대변득경강,원구형분관결미처적격파각비사변형분관소,분류조체작용경소;대우차류비익포국무인궤채용면적비위1?2~1?4적원구형분관,장획득교이상적기동성능。
Asymmetry nozzle of flying wing UAV ( Unmanned Aerial Vehicle ) was designed based on stealth and conformal requirements;this was set up into quadrilateral nozzle and circular-rectangle nozzle with different area ra-tios. The coupled numerical simulation was also carried out on the inflow/outflow integrated for flying wing UAV, and it is applied to studying the longitudinal aerodynamic performance of UAV and three-dimensional flow field characteristics of nozzle. Results and their analysis indicate: asymmetry nozzle of flying wing UAV can be used to improve the moment characteristic, and the lift/drag characteristic of circular-rectangle nozzle show better than quadrilateral nozzle;the convergent nozzle whose area ratio Ar≤1?0 will form the throat at the nozzle vent but not the design point expected at the engine vent, and that the strong shock will form at the throat which is not condu-cive for jet-flow to exhaust;with the increase of the area ratio, the axial thrust coefficient firstly increases and then decreases so that we could believe that there is an optimal area ratio, and that the circular-rectangle nozzle obtains better thrust performance than the quadrilateral nozzle along with the same area ratio;the intensity of shock wave al-so becomes stronger in the nozzle with increasing area ratio, and the shock wave angle formed at the root of circular-rectangle nozzle is smaller than quadrilateral nozzle which causes less blocking for jet-flow. Generally speaking, it is better to adopt circular-rectangle nozzle for the flying wing UAV with area ratio between 1?2 and 1?4;this leads to ideal aerodynamic performance.