The aerodynamic model of propeller,wing,fuselage and vertical tail are established for the tilt quad rotor(TQR)with partial tilt-wing,and then the flight dynamic model is established.Based on the six-degree-of-freedom...The aerodynamic model of propeller,wing,fuselage and vertical tail are established for the tilt quad rotor(TQR)with partial tilt-wing,and then the flight dynamic model is established.Based on the six-degree-of-freedom equation and the small disturbance linearization assumption,the trimming and stability of the tilt quad rotor with partial tilt-wing and the tilt quad rotor without tilt-wing are analyzed.The results show that in the hovering state,due to the existence of tilt-wing,the propeller wake reduces the downwash on the wing,thereby reducing the vertical weight gain of the aircraft.It is beneficial to increase the endurance time and improve the endurance performance.The transition corridor of the TQR with tilt-wing is narrower than that of the TQR without tilt-wing,but the transition corridor of TQR with tilt-wing still has a large space for design.Furthermore,the stability analysis shows that the Dutch roll damping ratio is larger,and in other modes the aircraft has a certain stability.The manipulation response analysis shows that in the transition mode the lateral-directional coupling is strong.展开更多
Conventional squeeze film dampers have numerous challenges including lock up,bistable response and incoordinate precession.In order to resolve these nonlinear problems,a novel G-type integral squeeze film damper(GISFD...Conventional squeeze film dampers have numerous challenges including lock up,bistable response and incoordinate precession.In order to resolve these nonlinear problems,a novel G-type integral squeeze film damper(GISFD)is proposed in this research.The experimental test rig is provided to investigate the rotor system with an unbalanced single disk.Numerical simulation results show that the structural design of GISFD is reasonable,which can ensure its safe and stable operation.The influence of different support stiffnesses on the first-order speed of the rotor system is analyzed.Experimental results show that GISFD can effectively suppress the unbalanced response vibration of the rotor.In a certain range,it is found that the suppression effect of GISFD increases with the increase in the kinematic viscosity of the damping fluid.When the silicone oil with kinematic viscosity coefficients v=30.0 cm^(2)/s is employed,the vibration reduction of GISFD is approximately 71.51%.Furthermore,the experimental results show that with the increase of the unbalance,there is a linear relationship between the unbalance and the corresponding amplitude of the unbalanced response.It is concluded that GISFD has excellent linear damping characteristics and reduces the sensitivity of the rotor system to the unbalanced mass.展开更多
针对冬季多能源耦合下的热电联产机组(combined heat and power,CHP)电功率调节能力受限于热功率输出,引起电-热联合系统灵活性不足的问题。该文提出了在网侧与负荷侧异质能流的惯性特征下计及用户温度动态响应以及动态反馈特性的联合...针对冬季多能源耦合下的热电联产机组(combined heat and power,CHP)电功率调节能力受限于热功率输出,引起电-热联合系统灵活性不足的问题。该文提出了在网侧与负荷侧异质能流的惯性特征下计及用户温度动态响应以及动态反馈特性的联合优化运行方法。首先,从建立CHP可行域与运行点的分布特性出发,分析了可再生能源并网后CHP机组运行灵活性不足原因,并给出了不可运行点重新回归CHP运行域优化的措施。其次,构建了传输侧惯性、负荷侧惯性影响下用户温度动态响应的多时间耦合特征双层模型,上层目标为热电异构能源系统总成本最低,下层目标为用能总效用最低。最后,引入了机会约束规划来刻画可再生能源的不确定性,通过算例结果表明,该文所提出方法在保证大量CHP运行点重新收束情况下,实现了可再生能源消纳与用户用能体验的兼顾。展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The aerodynamic model of propeller,wing,fuselage and vertical tail are established for the tilt quad rotor(TQR)with partial tilt-wing,and then the flight dynamic model is established.Based on the six-degree-of-freedom equation and the small disturbance linearization assumption,the trimming and stability of the tilt quad rotor with partial tilt-wing and the tilt quad rotor without tilt-wing are analyzed.The results show that in the hovering state,due to the existence of tilt-wing,the propeller wake reduces the downwash on the wing,thereby reducing the vertical weight gain of the aircraft.It is beneficial to increase the endurance time and improve the endurance performance.The transition corridor of the TQR with tilt-wing is narrower than that of the TQR without tilt-wing,but the transition corridor of TQR with tilt-wing still has a large space for design.Furthermore,the stability analysis shows that the Dutch roll damping ratio is larger,and in other modes the aircraft has a certain stability.The manipulation response analysis shows that in the transition mode the lateral-directional coupling is strong.
基金Supported by the National Science and Technology Major Project(No.2017-Ⅳ-0010-0047)the Fundamental Research Funds for the Central Universities(No.JD2003)。
文摘Conventional squeeze film dampers have numerous challenges including lock up,bistable response and incoordinate precession.In order to resolve these nonlinear problems,a novel G-type integral squeeze film damper(GISFD)is proposed in this research.The experimental test rig is provided to investigate the rotor system with an unbalanced single disk.Numerical simulation results show that the structural design of GISFD is reasonable,which can ensure its safe and stable operation.The influence of different support stiffnesses on the first-order speed of the rotor system is analyzed.Experimental results show that GISFD can effectively suppress the unbalanced response vibration of the rotor.In a certain range,it is found that the suppression effect of GISFD increases with the increase in the kinematic viscosity of the damping fluid.When the silicone oil with kinematic viscosity coefficients v=30.0 cm^(2)/s is employed,the vibration reduction of GISFD is approximately 71.51%.Furthermore,the experimental results show that with the increase of the unbalance,there is a linear relationship between the unbalance and the corresponding amplitude of the unbalanced response.It is concluded that GISFD has excellent linear damping characteristics and reduces the sensitivity of the rotor system to the unbalanced mass.
文摘针对冬季多能源耦合下的热电联产机组(combined heat and power,CHP)电功率调节能力受限于热功率输出,引起电-热联合系统灵活性不足的问题。该文提出了在网侧与负荷侧异质能流的惯性特征下计及用户温度动态响应以及动态反馈特性的联合优化运行方法。首先,从建立CHP可行域与运行点的分布特性出发,分析了可再生能源并网后CHP机组运行灵活性不足原因,并给出了不可运行点重新回归CHP运行域优化的措施。其次,构建了传输侧惯性、负荷侧惯性影响下用户温度动态响应的多时间耦合特征双层模型,上层目标为热电异构能源系统总成本最低,下层目标为用能总效用最低。最后,引入了机会约束规划来刻画可再生能源的不确定性,通过算例结果表明,该文所提出方法在保证大量CHP运行点重新收束情况下,实现了可再生能源消纳与用户用能体验的兼顾。
