A direct numerical modeling method for parachute is proposed firstly, and a model for the star-shaped folded parachute with detailed structures is established. The simplified arbitrary Lagrangian-Eulerian fluid struct...A direct numerical modeling method for parachute is proposed firstly, and a model for the star-shaped folded parachute with detailed structures is established. The simplified arbitrary Lagrangian-Eulerian fluid structure interaction （SALE/FSI） method is used to simulate the infla- tion process of a folded parachute, and the flow field calculation is mainly based on operator split- ting technique. By using this method, the dynamic variations of related parameters such as flow field and structure are obtained, and the load jump appearing at the end of initial inflation stage is cap- tured. Numerical results including opening load, drag characteristics, swinging angle, etc. are well consistent with wind tunnel tests. In addition, this coupled method can get more space-time detailed information such as geometry shape, structure, motion, and flow field. Compared with previous inflation time method, this method is a completely theoretical analysis approach without relying on empirical coefficients, which can provide a reference for material selection, performance optimi- zation during parachute design.展开更多
The growth of the low-altitude economy has led to an increase in the number of small aircraft and aviation equipment,thereby intensifying the demand for small-scale parachutes.Considering the limited attention to smal...The growth of the low-altitude economy has led to an increase in the number of small aircraft and aviation equipment,thereby intensifying the demand for small-scale parachutes.Considering the limited attention to small parachutes in existing research,this paper explores specialized parachutes with practical application value in framework of low-altitude economy.The Arbitrary Lagrangian–Eulerian(ALE)method was employed to analyze fluid-structure interaction(FSI)between parachute canopy and the surrounding air.The dynamic load curves demonstrate that at an inflow velocity of 10 m/s,the dynamic load peaks rapidly in less than 0.1 s during parachute opening,whereas at 50 m/s and 100 m/s,the time to peak is less than 0.03 s.The high-tension regions on the canopy's central surface exhibit an“X”-shaped distribution,with their area influenced by inflow velocity and inflation time,which informs the targeted reinforcement design for cruciform parachutes created by the simulation results in this study.A parachute airdrop test was conducted,and a combination of simplified model and drag coefficient correction is proposed to simulate the steady descent lift force.The relative error between simulation results of drag coefficient and the test data was found to be 4.49%.Simulation results show that the small-scale cruciform parachute in this study can carry an object with a mass of up to 10.18 kg,provided that the descent velocity is less than or equal to 10 m/s.The findings of this paper can provide a reference for the design and optimization of small-scale parachutes and help to assess their potential application in areas such as low-altitude economy.展开更多
基金co-supported by the National Natural Science Foundation of China (No. 11172137)the Aeronautical Science Foundation of China (No. 20122910001)
文摘A direct numerical modeling method for parachute is proposed firstly, and a model for the star-shaped folded parachute with detailed structures is established. The simplified arbitrary Lagrangian-Eulerian fluid structure interaction （SALE/FSI） method is used to simulate the infla- tion process of a folded parachute, and the flow field calculation is mainly based on operator split- ting technique. By using this method, the dynamic variations of related parameters such as flow field and structure are obtained, and the load jump appearing at the end of initial inflation stage is cap- tured. Numerical results including opening load, drag characteristics, swinging angle, etc. are well consistent with wind tunnel tests. In addition, this coupled method can get more space-time detailed information such as geometry shape, structure, motion, and flow field. Compared with previous inflation time method, this method is a completely theoretical analysis approach without relying on empirical coefficients, which can provide a reference for material selection, performance optimi- zation during parachute design.
基金supported by Shanghai Central Government Leading Local Science and Technology Development Funds(No.YDZX20233100004008).
文摘The growth of the low-altitude economy has led to an increase in the number of small aircraft and aviation equipment,thereby intensifying the demand for small-scale parachutes.Considering the limited attention to small parachutes in existing research,this paper explores specialized parachutes with practical application value in framework of low-altitude economy.The Arbitrary Lagrangian–Eulerian(ALE)method was employed to analyze fluid-structure interaction(FSI)between parachute canopy and the surrounding air.The dynamic load curves demonstrate that at an inflow velocity of 10 m/s,the dynamic load peaks rapidly in less than 0.1 s during parachute opening,whereas at 50 m/s and 100 m/s,the time to peak is less than 0.03 s.The high-tension regions on the canopy's central surface exhibit an“X”-shaped distribution,with their area influenced by inflow velocity and inflation time,which informs the targeted reinforcement design for cruciform parachutes created by the simulation results in this study.A parachute airdrop test was conducted,and a combination of simplified model and drag coefficient correction is proposed to simulate the steady descent lift force.The relative error between simulation results of drag coefficient and the test data was found to be 4.49%.Simulation results show that the small-scale cruciform parachute in this study can carry an object with a mass of up to 10.18 kg,provided that the descent velocity is less than or equal to 10 m/s.The findings of this paper can provide a reference for the design and optimization of small-scale parachutes and help to assess their potential application in areas such as low-altitude economy.
