W-型无尾气动布局研究

An Innovative W-shaped Tailless Aerodynamic Configuration

提出了一种新型的飞机气动外形—— W-型无尾布局及其气动设计思想 ,初步研究了两种气动布局方案 :前掠翼无尾气动布局和 W-型无尾气动布局。采用 Euler方程加附面层修正的数值分析方法 ,研究了两种布局的纵向气动性能 ,分析了翼身融合及机体大后掠侧缘对气动性能的影响。结果表明 ,W-型无尾气动布局具有良好的气动性能 ,其气动设计思想合理可行 ,具有良好的发展前景。

We present an innovative aerodynamic configuration of W-shaped tailless aircraft. Its design idea is based on the flow behavior of forward-swept wing and the flow control concept. Forward-swept wing is superior in subsonic lift-drag aerodynamic performance compared with other shape wings. Favorable outboard wing stall performance of forward-swept wing affords great potential in yaw and roll control ability which makes up the control deficiency of tailless aircrafts. The flow control technique and blended wing-body design for tailless configuration were adopted to achieve excellent aerodynamic characteristics. The high swept side strake can produce great energy vortex to control the flow separation at the root part of forward-swept wing to further improve aerodynamic performance at high angle of attack. Since its plane shape looks like letter “W”, we name it W-shaped configuration.In order to study the effect of blended wing-body and high swept side-strake on aerodynamic performance, two schemes are considered: forward-swept wing configuration (Fig.1) and W-shaped configuration (Fig.2). Longitudinal aerodynamic performance at M=0.3, Re=2.85×10 6 of these two configurations are analyzed with Euler method and boundary layer correction. The results as given in Fig.4 show that W-shaped tailless configuration is better in aerodynamic characteristics than forward-swept wing configuration in the following three respects: (1) favorable stall behavior: maximal lift value is C L=2.25 at α=32° (Fig.4(a)); (2) excellent lift-drag characteristics: K max =30.3, increased about 20% over the forward-swept wing configuration (Fig.4(c)); (3) good linear pitching moment (Fig.4(d)). Favorable aerodynamic characteristics are mainly due to two factors: (1) blended wing-body lifting body design improved lift-drag performance; (2) high swept side strake not only affords nonlinear vortex lift, but also achieves effective control on the flow separation at the root part of forward-swept wing.From the above, we can draw a conclusion that the aerodynamic design idea of W-shaped tailless configuration is reasonable and promising.