采用Navier-Stokes方程与滚转运动方程耦合计算方法,比较研究了不同后掠角的双三角翼和翼身组合体的滚转运动特性,分析了机翼前缘后掠角及细长机身对非定常滚转力矩时滞环、动态流场结构和物面瞬时压力分布的影响.研究结果表明:主翼迎风面上的融合涡能量在80°/60°双三角翼上耗散较小,而在76°/40°双三角翼上耗散严重,这是造成两模型滚转力矩稳定性与时滞特性差异的主要因素;机身对气流的扰动作用,大幅增强了滚转力矩的线性分量;机身对气流的上洗作用,增强了边条涡与融合涡吸力及其时滞性,同时加剧了主翼背风面的两涡干扰;大滚转角时机身对横流流动的干扰,使得主翼背风面压力分布的时滞差异显著增加.该研究结果有助于认识后掠角与细长机身影响双三角翼滚转运动特性的物理机理.
This paper establishes a coupled computation system which solves the Navier-Stokes equations and the rolling motion equation alternatively to obtain the rolling motion characteristics of two double delta wing models with different sweep angles and a wing-body configuration.It reveals the effect of the leading edge sweep angle and the slender body on the un steady rolling moment,the dynamic flowfield and the transient surface pressure distribution.The results show conclusively that the energy dissipation of the merged vortex upon the windward side of the 80°/60° double delta wing is much slighter than that upon the 76°/40° model.The merged vortex energy determines the time lag effect of the dynamic flowfield and the rolling moment.The presence of a slender body dramatically enhances the amplitude of the linear component of the rolling moment.Furthermore,the upwash airstreams around the slender body enhances the suction of the strake,the merged vortex suction and its hysteresis effect.The block of the cross flow caused by the slender body enlarges the time lag of the pressure distribution on the leeward side of the main wing.In general,these results may benefit the understanding for the mechanism of the effect of the sweep angle and slender body on rolling characteristics.