摘要：Aiming to maximize the aerodynamic performance of the Distributed Electric Propulsion(DEP)aircraft,a hybrid design framework which focuses on the aerodynamic performance of the propeller/wing integration has been developed and validated ***-fidelity modelling for propeller aerodynamics has been used to achieve computational efficiency with reasonable *** optimizing the aerodynamic loading distributions on the tractor propeller disk,the induced slipstream is redistributed into a form that is beneficial for the wing downstream,based on which the propeller blade geometry is generated through a rapid inversed design *** compared with the Minimum Induced Loss(MIL)propeller at a specified thrust level,significant improvements of both the lift-to-drag ratio of the wing and the propeller/wing integrated aerodynamic efficiency is achieved,which shows great promise to deliver aerodynamic benefits for the wing within the propeller slipstream without any additional devices.

摘要：Dragonflies have naturally high flying ability and flight maneuverability,making them more adaptable to harsh ecological *** this paper,a flapping wing bionic air vehicle with three-degrees-of-freedom is designed and manufactured by simulating the flight mode of ***,the body structure of dragonfly was analyzed,and then the design scheme of flapping wing micro air vehicle was proposed based on the flight motion characteristics and musculoskeletal system of *** optimizing the configuration and using Adams to do kinematic simulation,it is shown that the designed structure can make the wings move in an“8”shape trajectory,and the motion in three directions can maintain good consistency,with good dynamic *** on CFD simulation method,we analyzed that the wing has the conditions to achieve flight with good aerodynamic performance at the incoming flow speed of 5 m s^(-1)and frequency of 4 Hz,and studied the effects of angle of attack and flutter frequency on the aerodynamic performance of the ***,the force measurement test of the aircraft prototype is carried out using a force balance and a small wind *** test results show that the prototype can provide the average lift of 3.62 N and the average thrust of 2.54 N,which are in good agreement with the simulation results.

摘要：This paper presents the design of a centrifugal compressor for high-speed *** main focus of the research is to develop a centrifugal compressor with improved aerodynamic *** a meridional frame has a significant effect on overall performance of the compressor,special attention has been paid to the end wall *** shroud profile is design with bezier curve and hub profile with circular arc *** blade angle distribution has been arranged in a manner that it merges with single value at impeller *** rake angle is positive at leading edge and negative at trailing edge with identical ***,three-dimensional straight line element approach has been used for this design for better *** verification of the aerodynamic performance has been carried out using CFD software with consideration of a single blade passage and vaneless *** result has been compared with matching size aftermarket compressor stage gas stand *** compressor stage with Trim 55 provides 34%increase in choke flow at 210000 RPM as compared to gas stand data with 87%peak stage efficiency at 110000 *** addition,new surge margin improvement technique has been proposed by means of diffuser *** technique provides an average of 16%improvement in surge margin compared to standard diffuser stage with 55 trim compressor *** mechanical integrity has been validated at maximum RPM with the aluminum alloy 2014-T6 as a fabrication material.