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对定常状况下翼伞的流固耦合变形问题进行了三维数值模拟。使用有限体积法计算了飞行时的气动载荷,分析了前缘切口和翼肋开孔对压强分布的影响;基于翼伞结构大位移小应变的特点建立了非线性索膜有限元模型,伞衣由不能承受弯矩的膜单元模拟,伞绳和切口加强带由只能单向拉伸受力的索单元模拟,仿真了受气动载荷后翼伞相对于理想设计位置的变形和应力分布。结果表明:该翼伞展长相对于设计值减小,“鼓包”形成后翼型最大厚度增大,伞衣变形后产生了额外的后掠角和攻角;最大等效应力主要集中在翼肋上的开孔和伞绳连接点处,需合理布置加强带以满足强度要求。
The three-dimensional numerical simulation of the fluid-solid coupling deformation of the parafoil under steady conditions is carried out. The finite volume method was used to calculate the aerodynamic loads during flight. The influence of the leading edge incision and the rib opening on the pressure distribution was analyzed. Based on the characteristics of large displacement and small strain of wing structure, a nonlinear cable membrane finite element model was established. From the unbearable moment of the membrane element simulation, the umbrella rope and the incision reinforced by the cable unit can only be one-way tensile force simulation simulation of the aerodynamic load wing umbrella relative to the ideal design of the deformation and stress distribution. The results show that the length of the parafoil decreases with respect to the design value, the maximum thickness of the airfoil increases with the formation of the “bulge”, and the additional swept angle and angle of attack after the deformation of the parachute are generated. The maximum equivalent stress mainly concentrates in Ribs on the openings and the umbrella rope at the connection point, the need to rationalize the reinforcement belt to meet the strength requirements.