无人直升机系留气动载荷CFD计算分析

系留气动载荷作为无人直升机系留装置的设计输入，通常以机身大风侧向角气动特性风洞试验数据为基础进行计算。采用CFD计算方法对某无人直升机算例样机的机身大风侧向角气动特性进行了计算，包括自由来流、停放在开阔地面和船艉甲板3个状态，以机身气动特性CFD计算结果为基础计算了其系留气动载荷。结果表明:无人直升机在开阔地面停放时的系留气动载荷与自由来流时基本一致。而受船体上层建筑的影响，停放在船艉甲板时的系留气动载荷与自由来流时有较大的差别，除部分风侧向角状态的偏航力矩之外，力和部分力矩的绝对值相对较小，部分风侧向角状态的力和力矩方向相反。研究结果可为选取无人直升机系留气动载荷计算方法和不同停放环境下的机身气动特性的CFD计算及风洞试验状态提供一定的参考。 

CFD calculation and analysis of unmanned helicopter tie-down aerodynamic load

The tie-down aerodynamic load is used as the design input for the mooring device of the helicopter. In the past, it was usually calculated based on the wind tunnel test data of the large wind side angle aerodynamic characteristics of the fuselage. First, the CFD method was used to calculate the aerodynamic characteristics of the large wind side angle of an unmanned helicopter fuselage, including free flow, parking on the open ground and ship bow deck. Based on the CFD calculation results of the aerodynamic characteristics of the fuselage, the tie-down aerodynamic load was calculated. The results show that when the unmanned helicopter is parked on the open ground, the tie-down aerodynamic load is basically the same as that of the free flow. However, due to the influence of the ship's superstructure, the difference between the tie-down aerodynamic load when parked on ship bow deck and that of the free flow is large. The absolute values of force and part of the moment of force are relatively small, and the direction of the force and the moment of force are opposite in the case of some wind side angles. The research results can provide a certain reference for selecting the calculation method of helicopter tie-down aerodynamic load, the CFD calculation and the wind tunnel test status of the aerodynamic characteristics of the fuselage in different parking environments.