关键词: 无人机, 多体分离动力学, 内埋分离, 开伞等效, CFD-6DOF

Abstract:

The supply chamber can be internally carried in the Unmanned Aerial Vehicle （UAV）， and be separated in the target area by deploying a deceleration parachute swiftly. The agility and cost-effectiveness ratio of the airdropping can be improved significantly with this concept. However， the supply chamber is snugly assembled in the internal bay of UAV and has comparable mass with the UAV， which leads to stronger aerodynamic interference in the separation flow field. This is different from the separation of internal weapons from the combat aircraft. During the separation， the inflation and deployment of the deceleration parachute will cause highly unsteady flow fields and aerodynamic interference with the supply chamber and UAV. This makes it difficult for traditional methods based on the Arbitrary Lagrangian-Eulerian （ALE） method to analyze the impact of deployment of the deceleration parachute on the separation dynamic characteristics. In this paper， a parachute deployment equivalent method combining the inflation time method and wall assumption is proposed. By combining with Computational Fluid Dynamics （CFD） coupled with the 6 Degree Of Freedom （6DOF） equation method， an equivalent model of multi body separation accompanied by parachute deployment with Eulerian description is constructed. An integrated simulation analysis of the internal separation with the parachute deployment process for the supply chamber is achieved， and the impact of separation trajectory parameters and aerodynamic interference for the supply chamber is explored.Result shows that the proposed equivalent method can effectively analyze the deployment of the deceleration parachute. The trajectory of the supply chamber is relatively stable， while the UAV is affected by significant pitching interference during separation and parachute deployment. The impact of the analyzed variables on separation dynamics is nonlinear， and it is necessary to optimize the separation scheme further. Works in this paper can be the foundation for the design of UAV systems and separation schemes.

Key words: UAV, muti-body separation dynamics, internal separation, parachute deployment equivalent, CFD-6DOF