基于自由尾迹/面元法的旋翼下洗干扰计算和直升机配平

基于自由尾迹/面元法的耦合方法,建立了一种旋翼气动干扰模型和直升机配平计算模型.采用自由尾迹方法和升力面理论计算旋翼尾流带来的气动干扰,使用三维面元模型代替机身,采用涡镜像法模拟机身对尾迹的诱导和堵塞.以UH-60A直升机为算例,基于耦合方法,分别计算了旋翼尾迹形状以及尾迹对机身、平尾和尾桨的下洗速度,并与风洞试验结果对比.最后将自由尾迹/面元耦合法与直升机飞行力学模型嵌套,完成了配平计算,并与试飞结果和涡粒子模型计算结果进行了对比,结果的一致性证明了本方法的有效性.

Rotor downwash interference calculation and helicopter trims with free-wake/panel method

A coupled free-wake/panel method to predict the rotor downwash aerodynamic interaction and helicopter trims is presented. Based on lifting-surface theory, free-wake method was developed to analyze aerodynamics interference of rotor wake. A three dimensional panel model was applied to represent the fuselage, the vortex line mirror method was adopted to account for the induced and obstructed effects of the fuselage on the rotor wake. Based the coupled method, the rotor wake geometry and rotor downwash velocity on fuselage, horizontal stabilator and tail rotor of UH-60A helicopter were investigated including comparisons with the wind tunnel measured data. Combined with the helicopter flight dynamic model, the coupled method was embedded in the trim procedure and applied to trim. Comparisons among predictions, vortex particle model results and flight test results were for the control stick positions and attitude angles, coincidence of the results validated accuracy of the present methodology.