We present an efficient second- or fourth-order finite difference direct numerical simulation (DNS) solver using pencil-like domain decomposition parallel strategy, with the ability to handle different boundary conditions. The viscous term is treated implicitly, partial implicitly, or explicitly. The runtimes for different viscous treatments and different boundary conditions are evaluated quantitatively, which can help us to get a fast computational speed for specific flow cases. FFT-based method is used for solving Pressure Poisson equation, and alternating direction implicit approach is adopted for Helmholtz equations during the implicit viscous treatment. The numerical results achieve good match with those obtained from spectral methods. In addition, the resulting solver exhibits quite good parallel efficiency, and demonstrates good computational speedup and versatility than other pencil-like DNS solvers reported in the literature. The source code is freely available at https://github.com/GongZheng-Justin/Channel3d.

我们提出了一种使用铅笔状域分解并行策略的高效二阶或四阶有限差分直接数值模拟 (DNS) 求解器，能够处理不同的边界条件。粘性项被隐式、部分隐式或显式处理。对不同粘性处理和不同边界条件的运行时间进行定量评估，这可以帮助我们获得特定流动情况的快速计算速度。采用基于FFT的方法求解压力泊松方程，隐式粘性处理过程中对亥姆霍兹方程采用交替方向隐式方法。数值结果与光谱方法获得的结果很好地匹配。此外，由此产生的求解器表现出相当好的并行效率，与文献中报道的其他类似铅笔的 DNS 求解器相比，它展示了良好的计算速度和多功能性。源代码可在 https://github.com/GongZheng-Justin/Channel3d 免费获得。