Accuracy improvement of second-order central scheme using smart post-process filter for hybrid RANS/LES method
Accuracy improvement of second-order central scheme using smart post-process filter for hybrid RANS/LES method
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DOI：
10.1016/j.ast.2017.06.035
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发表时间：
2017-10
影响因子：
5.6
通讯作者：
R. Pasandeh;Vahid Esfahanian
中科院分区：
文献类型：
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作者：
R. Pasandeh;Vahid Esfahanian
本研究的目的是提出一种新的方法来提高计算代码采用RANS/LES技术与二阶中心格式的性能。为了实现这一点，非定常可压缩三维耦合RANS/LES求解器使用两方程湍流模型的开发。一个智能后处理滤波器也被嵌入作为耗散项在代码中，以保持稳定性和准确性。预先设计的传感器可检测数值解中非物理波动的量和位置，并控制智能后处理滤波器。详细的研究，以调查这种传感器和滤波器的性能。对可压缩高雷诺数流态的实验观察和数值结果的方法进行了验证。计算了NACA 0015翼型大迎角三维非定常绕流，以评价模型性能。结果表明，该方法对定常和非定常流场的模拟都具有良好的精度，特别是在大攻角情况下，考虑到流场分离现象，其他方法的精度通常会降低。
The present research aims to propose a new approach to improve the performance of computational codes employing the RANS/LES technique with 2nd order central scheme. To accomplish this, an unsteady compressible 3D coupled RANS/LES solver using two-equation turbulence model is developed. A smart post-processing filter is also embedded as the dissipation term in the code to maintain both the stability and the accuracy. A predesign sensor that detects the amount and position of non-physical fluctuations in numerical solution, controls the smart post-processing filter. Detailed study is performed to investigate the performance of this sensor and filter. The methodology is validated against several experimental observations and numerical findings for compressible high-Reynolds flow regimes. The unsteady 3D flow over a wing with NACA 0015 section at high angle of attack is computed to evaluate the model performance. The results indicate that the proposed methodology shows promising accuracy for both steady and unsteady flow simulations, especially in high angles of attack, in which the accuracy of the other schemes is normally decreased considering the flow separation phenomena.