降落伞充气过程的数值模拟

Numerical Simulation of Parachute During Opening Process

基于降落伞的重要应用与设计的实际需要,降落伞的数值模拟开始得到越来越多的重视,而充气过程是其中最为复杂的一个阶段。本文建立了平面圆形伞主充气过程中的CFD(Computational Fluid Dynamics)与结构动力学的MSD(Mass Spring Damper)之间的耦合模型。流场求解采用稳定性较高的标准k-ε模型,在多块贴体坐标下,获得某时间节点处的流场,并将该流场中的压力数据引入MSD模型,以获得下一时间节点的伞衣形状,最终获得主充气过程中伞衣形状和流场之间的动态关系。数值计算结果和实验结果及经验值比较,均有较好的一致性。充气过程的数值求解有助于提高对降落伞充气过程机理的理解。

For the requiremens of application and design,the numerical simulation of the parachute has aroused more and more attention. As the inflation process is the most complex stage in the whole working process of the parachute, the computation model of the canopy inflation which couples CFD（Computational Fluid Dynamics）to MSD（Mass Spring Damper） is set up. The standard κ-ε model is adopted in the calculation of the flow field. The flow-field of the parachute is simulated by the multiple block body-fitted grid generation method and the pressure field of canopy surface for the previous time step is imported to the MSD code. The canopy shape of the next time step is obtained by the MSD model and then provided it to the CFD code again. At last,the parachute shape and the flow field are gained during the opening process. The numerical values are well consistent with the experiental results and the experiment data. These numerical results are helpful to understand the mechanism of parachute inflation process.