飞艇大攻角绕流气动特性模拟及湍流模型与参数影响研究

AERODYNAMIC SIMULATION OF AIRSHIP AMBIENT FLOWS WITH HIGH ATTACK ANGLES AND ANALYSIS ON TURBULENCE MODELS AND PARAMETERS

  • 摘要: 飞艇大攻角绕流作为一种典型的分离与漩涡流动,相关研究具有较高难度和十分重要的意义。该文基于数值模拟方法,研究了飞艇大攻角绕流条件下的气动特性,分析了湍流模型选择和湍流强度设置等关键因素对模拟结果的影响。气动力、压力系数、流场显示细节等结果表明:SST 模型和Realizable 均能较准确地模拟飞艇周边流体流动现象,计算得到的气动参数和实验结果吻合良好,而S-A模型和实验存在较大差异;同时发现湍流强度对飞艇气动力存在较大影响,升阻力系数在湍流强度I > 0.5%时随之线性增长。进一步引入了等效雷诺数的概念,证明与原始雷诺数类似,等效雷诺数对气动力影响存在相应的敏感区间,在计算和实验中值得加以注意。

     

    Abstract: Airship ambient flows with high attack angles were studied, including separated flows and vortex motions. In this paper, aerodynamic characteristics of airship ambient flows with high attack angles were investigated numerically. Turbulence models and turbulence intensity were also considered. Numerical results provided detailed aerodynamic information of flows around the airship, such as distributions of circumferential and radial pressure coefficients, oil flow distributions and aerodynamic forces with different turbulence models. Results show that SST and Realizable are more suitable for the aerodynamic simulation than S-A. Moreover, lift and drag coefficients vary linearly with the turbulence intensity I when I > 0.5%. The concept of equivalent Reynolds number is introduced, which is found to have great effects on aerodynamic characteristics within a certain range.

     

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