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飞艇作为临近空间高分辨率观测的重要平台,力学性能研究非常重要。飞艇的主体材料一般由柔性蒙皮构成,容易在气动作用下产生较大的变形,存在较强的流固耦合效应,是其力学性能研究的关键。该文采用松耦合方法形成了定常流固耦合计算方法,并且针对流场与结构的模型展开了详细的计算,和实验结果进行了验证。针对不同刚度构型飞艇模型的计算结果显示:硬式飞艇不需考虑流场和结构的耦合效应,半硬式和软式飞艇的耦合效应较明显。其中半硬式飞艇,耦合效应主要影响区域为柔性最大的橡胶部分,考虑耦合效应后,飞艇位移变形量增加约5%。软式飞艇,变形最为明显的是飞艇的尾部和头部,在来流作用下会出现明显的抬头位移,最大位移增量为225%。此外还采用量纲分析方法,得到了艇体变形与膜材料弹性模量、内压、来流的变化规律。当模型与实物满足几何相似、材料相似和动力学相似的条件下,变形将满足几何相似律。
Airships as an important platform for high-resolution near-space observations, the study of mechanical properties is very important. The main material of the airship is generally composed of flexible skin. It is easy to produce large deformation under aerodynamic action, and strong fluid-solid coupling effect exists, which is the key of its mechanical properties. In this paper, a loosely coupled method is used to form a steady-state fluid-structure interaction calculation method, and a detailed calculation of the flow field and structure model is carried out. The experimental results are also validated. The calculation results of the airship model with different stiffness configurations show that the coupling effect of the flow field and the structure is not considered in the rigid airship, and the coupling effect between the semi-rigid and airship is obvious. Semi-rigid airship, the coupling effect of the main impact of the region for the most flexible rubber part, taking into account the coupling effect, the displacement of the airship displacement increased by about 5%. Airship, the most obvious deformation is the airship tail and head, in the flow under the action will appear significant head-up displacement, the maximum displacement increment of 225%. In addition, dimensional analysis method was used to obtain the variation of hull deformation and elastic modulus of membrane material, internal pressure and incoming flow. When the model and the physical meet the geometric similarity, material similarity and kinetics similar conditions, the deformation will meet the geometric similarity law.