飞艇空气动力学及其相关问题

对低空和高空飞艇在发射、回收、驻留、巡航或系留状态下所涉及的空气动力学问题及其重要性进行分析,介绍飞艇空气动力学研究的进展和主要结论,指出需要进一步解决的问题。低空飞艇的空气动力学问题主要包括厚艇身带来的流动分离与减阻、非薄平组件的非线性干扰、柔弹性表面或系留带来的流固耦合、因低速飞行带来的环境敏感性等。大量学者进行了相应的研究。高空即平流层飞艇还涉及多种新的空气动力学问题,包括热、浮力与气动的强耦合、昼夜外形变化、发射与回收过程中的突风带影响、风切变干扰等。关于这些问题的研究处于起步阶段。另外,还针对地面及大气边界层的影响、多边形外形以及副气囊喷流与主流干扰等很少有人研究的问题对飞艇周边流场进行了初步数值模拟。

Some Aerodynamics Problems of Airship

In this article, some aerodynamics problems and the importance for both low and high altitude airships while launching, recovering, hovering or tethered are analyzed. Development and achievement of airship dynamics research are introduced, and some problems which need further study are also pointed out. The aerodynamics problems of low altitude airships consist of the flow separation and drag reduction for blunt hulls, nonlinear interactions of non-flat components, fluid-structure interaction due to flexible envelope or tethering, and sensitivity to environment due to low speed, etc. Many researchers have been working on these problems. High altitude airships also involve some extra aerodynamics problems including coupling with thermal and buoyance, shape deforming between day and night, response to turbulence during launch or recovery, shear of wind, etc, the studies of which are still at the starting stage. In addition, we preliminarily and numerically simulate the ambient flow field around airships, considering the influences of the ground and atmospheric boundary layer, polygonal cross-sectioned hulls, interaction between the jet flow from ballonets and the incoming flow, which are relatively less studied.