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为研究不同球体间距对“球形囊体型”平流层浮空器(SLV)气动特性的影响,采用有限体格式、结构网格和大涡模拟(LES)计算方法求解不可压缩的Navier-Stokes(NS)方程,对超临界雷诺数“球形囊体型”平流层浮空器绕流进行数值模拟,并对不同球体间距下的数值计算结果进行详细的分析比较.通过对比试验数据,单球体数值模拟的阻力系数时均值与Achenbach的试验数据一致,验证了计算方法分析超临界雷诺数球体绕流问题的准确性.研究不同间距的双球体阻力变化规律以及振动频谱特性,随上下游球体间距G的增加,合阻力先增大后减小,上游球体的阻力占优振动频率逐渐减小;G=1.5D(D为球体直径)和G=2D时,上下游球体有相同的占优振动频率.随间距G的增加,两球体相互作用与上游球体对下游球体的尾涡结构影响逐渐减弱.
In order to study the influence of different ball spacings on the aerodynamic characteristics of the “spherical capsule” stratospheric aerostatics (SLV), finite element schemes, structural meshes and large eddy simulations (LES) were used to solve the incompressible Navier-Stokes (NS) equation, the numerical simulation of the flow around the supercritical Reynolds number “spherical capsule” stratospheric aerostat is carried out, and the numerical calculation results under different sphere spacings are analyzed and compared in detail. By comparing the experimental data, The mean value of the drag coefficient of the sphere numerical simulation is in agreement with the experimental data of Achenbach, which verifies the accuracy of the calculation method for analyzing the flow around the supercritical Reynolds number sphere. The variation of the drag of the double sphere with different pitches and the vibration spectrum characteristics are investigated. When G = 1.5D (D is the sphere diameter) and G = 2D, the upper and lower spheres have the same predominance With the increase of G, the interaction between the two spheres and the influence of the upstream sphere on the vortex structure of the downstream sphere gradually weakened.