The development of the Urban Air Mobility concept has proposed stringent requirements for the fixed-wing vehicle’s Short/Vertical Take-Off and Landing(S/VTOL)performance.With its lift-enhancing impact,the channel win...The development of the Urban Air Mobility concept has proposed stringent requirements for the fixed-wing vehicle’s Short/Vertical Take-Off and Landing(S/VTOL)performance.With its lift-enhancing impact,the channel wing,can improve aircraft low-speed performance and Short Take-Off and Landing(STOL)capability.It is critical for the performance analysis and flow mechanism study of a channel wing that considers the influence of propeller slipstream to guide the design of S/VTOL aircraft.The law and mechanism for the effect of the enclosing angle of the arc wing,the phase angle of the propeller,the tip clearance,the rotational speed and the chordwise position of the propeller on the channel wing are explored utilizing the quasi-steady multi reference frame method.A channel wing with a larger enclosing angle has a better ability to enhance lift and reduce drag using propeller slipstream.The effect of propeller phase angle on channel wing aerodynamic forces is periodic and weak.Increasing propeller rotational speed is helpful to enhance lift and resist flow separation for channel wing.It can reduce drag for tractor configuration but increase drag for pusher configuration.However,the nose-down pitching moment of a channel wing will grow dramatically,making longitudinal trimming in aircraft layout design challenging.展开更多
The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dime...The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dimensional(2.5D)high-lift wing design approach considering the three-dimensional(3D)effects of slipstream for DEP aircraft,aiming at maximizing the comprehensive lift enhancement benefit of the airframe-propulsion coupling unit.A high-precision and efficient momentum source method is adopted to simulate the slipstream effects,and the distributed propellers are replaced by a rectangular actuator disk to reduce the difficulty of grid generation and improve the grid quality.A detailed comparison of the 2.5D and 3D configurations based on the X-57 ModⅣis performed in terms of flow characteristics and computational cost to demonstrate the rationality of the above design approach.The optimization results of the high-lift wing of the X-57 ModⅣshow that the aerodynamic performance of the landing configuration is significantly improved,for instance,the lift coefficient increases by 0.094 at the angle of attack of 7°,and 0.097 at the angle of attack of 14°.This novel approach achieves efficient and effective design of high-lift wings under the influence of distributed slipstream,which has the potential to improve the design level of DEP aircraft.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(No.D5000220505)the Central Funds Guiding the Local Science and Technology Development,China(No.2021Szvup1).
文摘The development of the Urban Air Mobility concept has proposed stringent requirements for the fixed-wing vehicle’s Short/Vertical Take-Off and Landing(S/VTOL)performance.With its lift-enhancing impact,the channel wing,can improve aircraft low-speed performance and Short Take-Off and Landing(STOL)capability.It is critical for the performance analysis and flow mechanism study of a channel wing that considers the influence of propeller slipstream to guide the design of S/VTOL aircraft.The law and mechanism for the effect of the enclosing angle of the arc wing,the phase angle of the propeller,the tip clearance,the rotational speed and the chordwise position of the propeller on the channel wing are explored utilizing the quasi-steady multi reference frame method.A channel wing with a larger enclosing angle has a better ability to enhance lift and reduce drag using propeller slipstream.The effect of propeller phase angle on channel wing aerodynamic forces is periodic and weak.Increasing propeller rotational speed is helpful to enhance lift and resist flow separation for channel wing.It can reduce drag for tractor configuration but increase drag for pusher configuration.However,the nose-down pitching moment of a channel wing will grow dramatically,making longitudinal trimming in aircraft layout design challenging.
文摘The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dimensional(2.5D)high-lift wing design approach considering the three-dimensional(3D)effects of slipstream for DEP aircraft,aiming at maximizing the comprehensive lift enhancement benefit of the airframe-propulsion coupling unit.A high-precision and efficient momentum source method is adopted to simulate the slipstream effects,and the distributed propellers are replaced by a rectangular actuator disk to reduce the difficulty of grid generation and improve the grid quality.A detailed comparison of the 2.5D and 3D configurations based on the X-57 ModⅣis performed in terms of flow characteristics and computational cost to demonstrate the rationality of the above design approach.The optimization results of the high-lift wing of the X-57 ModⅣshow that the aerodynamic performance of the landing configuration is significantly improved,for instance,the lift coefficient increases by 0.094 at the angle of attack of 7°,and 0.097 at the angle of attack of 14°.This novel approach achieves efficient and effective design of high-lift wings under the influence of distributed slipstream,which has the potential to improve the design level of DEP aircraft.
