硬式飞艇氦气囊的非饱和形态研究

Study on Unsaturated Morphology of Helium Bag in Rigid Airship

硬式飞艇升空前其内置氦气囊充气比例(饱和度)小于100%,氦气囊是非饱和的。氦气囊的非饱和形态影响飞艇内置氦气囊的布局形式和重心位置。为了研究硬式飞艇氦气囊的非饱和形态变化规律,首先将采用控制体积法获得的氦气囊的饱和形态作为初始状态,利用任意拉格朗日–欧拉方法模拟氦气囊的泄气过程,获得了气囊和流场之间的动态关系、不同饱和度的气囊形态及内压等主要参数。然后进行了地面氦气囊泄气试验,并将数值计算结果与试验结果进行了对比。结果表明,泄气初始阶段囊体的外形变化较小,气囊中上部维持饱和形态不变,气囊底部及其两侧形状最先变化;随着饱和度的降低,囊体底部被挤压的区域逐渐向上移动,囊内压力逐渐降低。该研究可为飞艇氦气囊设计及氦气囊的布局形式提供参考。

Before the rigid airship lifts off,its built-in helium bag inflation ratio(saturation)is less than 100%,and the helium bag is unsaturated.The unsaturated form of the helium bag affects the layout and center of gravity of helium bag in airship.In order to study the unsaturated shape of the helium bag in the rigid airship.Firstly,the saturated shape of the helium bag obtained by the Control Volume(CV)method is used as the initial state,and the deflation process of the helium bag is simulated by the arbitrary Lagrange-Euler(ALE)method,the main parameters such as the dynamic relationship with the flow field,the shape of the helium bag with different saturation and internal pressure of the helium bag are gained during the numerical simulation.Then,the helium bag deflation test is carried out on the ground,the results between the simulation and tests are compared.The results show that the shape of the helium bag changes little in the initial stage of deflation,the middle and upper region of the helium bag maintain the saturation shape,and the shape of the bottom and both sides of the helium bag changes first.With the saturation decreases,the compressed area at the bottom of the bag gradually moves upward,and the pressure in the bag gradually decreases.The research can provide several references on the design of helium bag and the layout of helium bags.