十字形伞有限质量充气展开及尾流再附现象

The finite mass inflation characteristics and wake recontact phenomenon of folded cross parachutes are investigated. The fluid-structure interaction numerical simulation is conducted using the arbitrary Lagrangian-Eulerian (ALE) method for the cross parachute-load system with mass ratio from 0. 17 to 0. 94 and Froude number from 6. 8 to 383. 9 during deceleration. The effects of the mass ratio and Froude number on the inflation process of cross parachute are studied. The peak deployment load and canopy collapse parameter are discussed. The phase diagrams for the three different inflation results of cross parachute, namely, normal inflation, reinflation after wake recontact, and complete failure after wake recontact, are plotted in relation to the mass ratio and Froude number. The three inflation processes of cross parachute are analyzed in detail. The deployment load, drag coefficient, and transient change in the projected diameter of canopy are studied, and the fluid-structure interaction mechanisms of different inflation processes are studied by taking into account the structural deformation of parachute, stress distribution and unsteady flow field. The results indicate hat the dimensionless peak deployment load and canopy collapse parameter increase with the increase in Froude number. During the finite mass inflation process of parachute, there is intense momentum exchange between the canopy and air around it, which may lead to high-speed wake flow interacting with the canopy to cause a significant collapse or even complete collapse of the cross parachute.