Study On The Feasibility Of Variant Quad-rotor UAV

Quad-rotor UAVs have been used in many fields due to its advantages of vertical take-off and landing and high reliability.However,the contradiction between accessibility and payload prevented its further application in the rescue in building or forest,and in the special reconnaissance.A new variant quad-rotor unmanned air vehicle(UAV)is presented,the purpose is to provide quite well payload and quite good accessibility at same time.The establishment and optimization of the three-dimensional geometric model of the new variant quad-rotor UAV have been completed,and the simulation verified the rationality of its configuration.A bench test and a CFD numerical simulation was carried out for the propeller used,and the two results were compared and verified the correctness of the simulation.The CFD simulation is used to analyze the aerodynamic characteristics in a typical configuration of the new UAV,and the configuration has been optimized based on the results.According to the optimization results,a physical prototype was built and hovering test flight performed,which verified the feasibility of the variant,the rationality of the configuration and the correctness of the simulation.The results show that: 1)The size can be reduced as much as41.4%,and the area can be reduced as much as 63.8%.2)The maximum error between the pull forces that the propeller produced and CFD simulated is 1.85%,and the minimum error is as low as 0.212%.3)After optimization,the maximum reduction of drag produced by airframe reached 104.1%,and the maximum increase of lift was 5.0%.4)Stable variant was realized during the hovering test.5)The actual weight of the prototype is about equal to that of a conventional non-variant quad-rotor UAV with similar maximum size.Conclusion: 1)The configuration,aerodynamic performance,variant mode,driving capability and control mode of the new variant quad-rotor UAV presented are feasible.2)The optimization is reasonable by using of CFD.