Research on the influence of length-width ratio on cruciform parachute airdropping performance

Different from the other design parameters in general drogues, there are few studies about the parameter of Length-Width Ratio (LWR). Therefore, the fluid structure coupling model based on the Finite Element Method was used to study the deceleration characteristics and terminal trajectory stability of parachute system in this work. And the graphic transformation technology commonly used in Computer Graphics was used to realize the following of flow field with the trajectory movement. In this work, the cruciform parachutes with different LWR were taken as the research objects, and the above method was used to obtain the trajectory curves, deceleration characteristic curves, and stability curves of the cruciform parachutes under different external conditions. It was found that the deceleration performance was negatively correlated with the LWR when the other design parameters and working conditions remained unchanged, and the trajectory stability and the stability of the parachute were positively correlated with the LWR. Subsequently, the cruciform parachute with the LWR of 4.5 was used for airdropping test, and the accuracy of numerical method used in this work was verified. Then the deceleration processes of cruciform parachute (LWR: 4.5) under different dropping conditions were calculated. It could be found that the external launching conditions had a limited impact on the deceleration performance. The LWR was another design parameter that had a greater impact on the deceleration performance after the parameter of canopy area. Finally, the drag coefficient correction equation representing the deceleration performance was proposed for the first time.