关键词: 流固耦合, 数值仿真, 浮空气球, ALE法, 降落伞

Abstract: In the deployment process of the Venus balloon probe, the balloon needs to be decelerated by the parachute to inflate in the air. The aerodynamic drag of the parachute-balloon combination is a factor that needs to be considered in the scheme design. For this issue, a fluid-structure interaction numerical model is established for the parachute-balloon combination. In this model, the flow field is solved using the ALE (Arbitrary Lagrange-Euler) method, and the fluid mesh follows the motion of the parachute-balloon combination. The penalty function method is used to handle the fluid-structure interaction between the flow field and the parachute and balloon, as well as the structural self-contact of the parachute and balloon. The internal pressure and volume changes of the balloon are solved by the CV (Control volume) method. The partially inflated balloon shape is obtained through compression by setting the initial internal pressure of the balloon. The buoyancy of the balloon is achieved by applying a pressure difference that varies with height on the surface of the balloon. Using this model, simulations are conducted on the process of partially inflated balloon parachute descending in the atmospheric environment of Venus, and the impact of changes in balloon inflation rates on the calculation results is analyzed. The calculation results indicate that the balloon shape undergoes slight changes over time under the influence of the flow field, and the balloon rotates. The drags of the balloon and para-chute fluctuate significantly over time, and their fluctuation frequencies are basically the same. The inflation rate change has no significant effect on the fluctuation frequency. As the inflation rate increases, the average drag of the balloon increases, while the average drag of the parachute remains basically unchanged. The areas of the balloon sorted in order of stress from high to low are as follows: flange fringes and wrinkles of the balloon, the filled area at the top of the balloon, depressed areas of the balloon.

Key words: fluid-structure interaction, numerical simulation, balloon, ALE method, parachute