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An improved dealiasing scheme for the fourth‐order Runge‐Kutta method: Formulation, accuracy and efficiency analysis
International Journal for Numerical Methods in Fluids ( IF 1.7 ) Pub Date : 2020-07-21 , DOI: 10.1002/fld.4898
Arijit Sinhababu 1 , Sathyanarayana Ayyalasomayajula 1
Affiliation  

In this paper, the Random Phase Shift Method (RPSM) dealiasing scheme has been developed with the classical fourth‐order explicit Runge‐Kutta (RK4) method. This scheme is implemented in different benchmark problems to verify its numerical accuracy and computational efficiency where strong gradients are present in the solution. The propagation of aliasing errors through the substeps of RK4 is derived to show the existence of the residual aliasing error terms which results in mild smoothing effect without dissipating the small‐scale flow structures. Smoothness and numerical stability in the solutions obtained from the RPSM scheme also remain well preserved even at under‐resolved conditions. Numerical results agree well with the analytical and the computed solutions from previous studies. RPSM scheme shows a slight delay in the formation of numerical singularity for the inviscid flows but the filtering‐based schemes suffer from early blow‐up problem. We observe that this scheme displays better resolving ability than higher‐order exponential smoothing spectral filter scheme in capturing the strong fronts accurately even at just resolved spatial grid resolutions. Three‐dimensional truncation‐based dealiasing scheme, spherical truncation (SPT) shows vortices generated due to the parasitic currents in the solution of the inviscid three‐dimensional Taylor Green (TG) vortex flows. RPSM displays only the accurate isocontours of vortical field at nearly same computational expenses as the SPT scheme.

中文翻译:

四阶Runge-Kutta方法的改进的脱脱方案:配方,准确性和效率分析

本文采用经典的四阶显式Runge-Kutta(RK4)方法开发了随机相移方法(RPSM)去杂方案。在解决方案中存在强梯度的情况下,在不同的基准问题中实施此方案以验证其数值准确性和计算效率。推导了混叠误差在RK4子步骤中的传播,以显示残留混叠误差项的存在,这将导致适度的平滑效果而不会耗散小规模的流动结构。即使在欠解决的条件下,从RPSM方案获得的解的光滑度和数值稳定性也保持良好。数值结果与先前研究的解析解和计算解非常吻合。RPSM方案在无粘性流的数值奇异点的形成上显示了轻微的延迟,但是基于过滤的方案存在早期爆炸问题。我们观察到,即使在仅解析的空间网格分辨率下,该方案也比高阶指数平滑光谱滤波器方案具有更好的分辨能力,可以准确地捕获强前沿。基于三维截断的脱硝方案,球形截断(SPT)显示了由于无粘性的三维泰勒格林(TG)涡流解中的寄生电流而产生的涡流。RPSM仅显示旋涡场的精确等值线,而计算费用与SPT方案几乎相同。我们观察到,即使在仅解析的空间网格分辨率下,该方案也比高阶指数平滑光谱滤波器方案具有更好的分辨能力,可以准确地捕获强前沿。基于三维截断的脱硝方案,球形截断(SPT)显示了由于无粘性的三维泰勒格林(TG)涡流解中的寄生电流而产生的涡流。RPSM仅显示旋涡场的精确等值线,而计算费用与SPT方案几乎相同。我们观察到,即使在仅解析的空间网格分辨率下,该方案也比高阶指数平滑光谱滤波器方案具有更好的分辨能力,可以准确地捕获强前沿。基于三维截断的脱硝方案,球形截断(SPT)显示了由于无粘性的三维泰勒格林(TG)涡流解中的寄生电流而产生的涡流。RPSM仅显示旋涡场的精确等值线,而计算费用与SPT方案几乎相同。球形截断(SPT)显示了由于无粘性三维泰勒格林(TG)涡流解中的寄生电流而产生的涡流。RPSM仅显示旋涡场的精确等值线,而计算费用与SPT方案几乎相同。球形截断(SPT)显示了由于无粘性三维泰勒格林(TG)涡流解中的寄生电流而产生的涡流。RPSM仅显示旋涡场的精确等值线,而计算费用与SPT方案几乎相同。
更新日期:2020-07-21
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