Unsteady Simulation of the Separated Wake of a Transport Aircraft by Detached Eddy Simulation
Unsteady Simulation of the Separated Wake of a Transport Aircraft by Detached Eddy Simulation
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分离涡模拟对运输机分离尾流的非定常模拟
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
E. Krämer
中科院分区：
文献类型：
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作者：
A. Waldmann;T. Lutz;E. Krämer
本文总结了近年来利用分离涡模拟（DES）方法模拟商用运输机结构中大规模分离尾流的研究成果。针对非定常模拟，定义了两种网格分辨率和两种时间步长，旨在改进这类模拟的现有最佳实践。对结果的统计收敛所需的时间步数进行了评估。在流场中，对运行结果的比较表明，降低物理时间步长增加了尾迹中的速度亏缺。相比之下，时间步长对翼附近大尺度湍流结构产生的影响较小。网格分辨率的降低强烈影响了前缘剪切层的预测，导致机翼上的压力波动显著降低。对流平均通量的离散化在剪切层分离中起着重要的作用。
The work summarizes recent efforts concerning the simulation of massively separated wake flows of commercial transport aircraft configurations via detached-eddy simulation (DES). Two levels of grid resolution and two time step sizes were defined for the unsteady simulation runs, with the aim of improving the existing best practices with respect to this type of simulation. The number of time steps required for statistics convergence of the results is evaluated. In the flow field, comparisons of the results between the runs show that lowering the physical time step increases the velocity deficit in the wake. By comparison, the time step’s impact on the generation of large-scale turbulent structures near the wing is smaller in magnitude. The reduction of grid resolution strongly impacts prediction of the leading edge shear layer, leading to significantly lower pressure fluctuations on the wing. The discretization of convective mean flow fluxes was observed to play a significant role in the context of shear layer separation.