二维翼型下表面增升辅助装置仿真及设计

为提高飞翼布局飞机的可用升力系数,以B-29 TIP翼型为研究对象,基于CFD开展了翼型腹部加装扰流板以配平增升装置打开后带来的低头力矩可行性研究,获得了腹部扰流板的作用原理,总结了扰流板弦向位置、偏度及高度对翼型气动特性的影响规律,以及扰流板与翼型后缘襟翼偏转的组合状态的气动特性。研究结果表明:腹部扰流板可改变翼型下表面流场的压力分布,扰流板前正压增大,扰流板后负压增大,从而产生抬头力矩。随扰流板弦向位置的后移,抬头力矩先增后减,于60%翼型弦长位置处达到最大值,升力先减后增,于40%翼型弦长位置处达到最小值。随高度及偏角的增大,抬头力矩单调递减,升力单调递增。

Simulation and Design of Belly Auxiliary Device of Lift-enhancementon the Bottom of Two-dimensional Airfoil

In order to improve the available lift coeficient of aircraft with flying wing configuration .taking B-29 ''TIP airfoil as the research object, the feasibility of installing spoiler in the belly of airfoilto balance the nose-down pitch moment after opening the lifting device was studied by CFD. Theworking principle of belly spoiler was obtained. The influence of geometric parameters such as chordposition , height and delection angle of spoiler on aerodynamic characteristies of airfoil and the aero.dynamic character of the combination of spoiler and airfoil which trailing edge is deflected are sum.marized. The main results include that the belly spoiler can change the pressure distribution of the air.foil abdominal flow field, the positive pressure in front of the spoiler is increased,the negative pres.sure behind the spoiler is increased , so a nose-up pitch moment comes into being. With the backwardof spoiler, the nose-up pitch moment will increase at first and then decrease ,and reach the maximumwhen spoiler is at the maximumwhen spoiler is at the position of 6096 chord length; the lift will decrease at first and then increase ,and reach the minimum when the spoiler is at the position of 40%6 chord length. With the increase olheight and deflection of spoiler ,the nose-up pitch moment will monotone decrease , the lift will mon-otone incrase.