A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program....A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.展开更多
In response to the issues posed by non-biodegradable orchard fruit pouches causing environmental pollution,as well as the inefficiency and high cost of manual recovery,a design for an orchard fruit pouch collecting ma...In response to the issues posed by non-biodegradable orchard fruit pouches causing environmental pollution,as well as the inefficiency and high cost of manual recovery,a design for an orchard fruit pouch collecting machine was proposed.The study involved analyzing the structure and working principle of the entire machine,as well as proposing two types of pick-up and recovery devices:a spring-tooth roller type pickup device and an air-suction collecting device.After comparative analysis,the spring-tooth roller type pickup device was selected.Based on the physical characteristics of the fruit pouch,theoretical calculations and kinematic analysis were performed for the key components of the orchard fruit pouch collecting machine.This analysis yielded working parameters for each component,with a focus on roller rotational speed,machine travel speed,and number of spring-tooth rows as critical factors influencing operational effectiveness.Subsequently,the ADAMS simulations were conducted based on these findings.Then the response surface methodology was applied,and an optimal parameter combination for the orchard fruit pouch collecting machine was determined:a machine travel speed of 2 km/h,roller rotational speed of 60 r/min,and five rows of spring teeth.The prototype was made,and the results of orchard experiments indicated that with the optimal parameter combination,the recovery rate predicted by the model was 85.2%and that of the orchard experiment was 80.9%.The relative error between them is 5.3%.These findings confirmed that the designed orchard fruit pouch collecting machine could achieve the expected performance and effectively recover fruit pouches with good efficiency.展开更多
基金Supported by the National Natural Science Foundation Programme of China(No.61374145)
文摘A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.
基金National Natural Science Foundation of China(Grant No.31971801)Shandong Provincial Natural Science Foundation of China(ZR2020ME252,ZR2020ME250)Qingdao Demonstration Project(25-1-5-xdny-33-nsh).
文摘In response to the issues posed by non-biodegradable orchard fruit pouches causing environmental pollution,as well as the inefficiency and high cost of manual recovery,a design for an orchard fruit pouch collecting machine was proposed.The study involved analyzing the structure and working principle of the entire machine,as well as proposing two types of pick-up and recovery devices:a spring-tooth roller type pickup device and an air-suction collecting device.After comparative analysis,the spring-tooth roller type pickup device was selected.Based on the physical characteristics of the fruit pouch,theoretical calculations and kinematic analysis were performed for the key components of the orchard fruit pouch collecting machine.This analysis yielded working parameters for each component,with a focus on roller rotational speed,machine travel speed,and number of spring-tooth rows as critical factors influencing operational effectiveness.Subsequently,the ADAMS simulations were conducted based on these findings.Then the response surface methodology was applied,and an optimal parameter combination for the orchard fruit pouch collecting machine was determined:a machine travel speed of 2 km/h,roller rotational speed of 60 r/min,and five rows of spring teeth.The prototype was made,and the results of orchard experiments indicated that with the optimal parameter combination,the recovery rate predicted by the model was 85.2%and that of the orchard experiment was 80.9%.The relative error between them is 5.3%.These findings confirmed that the designed orchard fruit pouch collecting machine could achieve the expected performance and effectively recover fruit pouches with good efficiency.
