带地效翼型俯仰控制技术研究

Investigation on pitch control technique for an airfoil with ground effect

为解决飞翼布局起降状态俯仰控制能力不足问题,研究一种新型的腹部扰流板俯仰控制装置。针对带地效翼型,采用数值计算方法,研究了扰流板高度、弦向位置、偏度、迎角、离地高度等参数对俯仰与升阻性能的影响及其流动机理,给出了扰流板设计原则。研究结果表明,在地效作用下,合适的扰流板弦向位置和高度与偏度配合,可提供显著的抬头力矩增量和较大的升力增量,有助于提高飞机起降性能。针对附加的较大阻力增量,扰流板面开孔影响探索性研究表明,开孔可减小附加阻力,提高升阻比,但使抬头力矩增量有所减小。扰流板是一种改善无尾飞翼布局俯仰操纵的有效措施,值得深入研究。

Aim to the pitch control problem of flying-wing configuration, a novel simple pitch control effector called a belly-flap is investigated to increase nose-up couple efficiently without unacceptable lift loss in this paper. Two-dimensional Reynolds-averaged Navier-Stokes calculations for various belly-flap configurations applied to an airfoil are described, and results are presented. The geometry parameters （size, location, deflection angle ）, ground effect and angle of attack are studied to detect their effects on the aerodynamic characteristics. The researches show that the optimized belly-flap can improve aerodynamic performance in take-off and landing conditions by bringing obvious increments in pitch up moment and lift. Aim to the additive drag increment complied with the bel- ly-flap, many holes are disposed on the belly-flap. The researches show that those holes can decrease the additive drag and increase lift-drag ratio with few decrease in the pitch up moment. In conclusion, the belly-flap is an effective pitch control effector for the blended-wing-body in take-off and landing conditions.