Refaie Ali Ahmed, Abbasi Waqas Sarwar, Bibi Bakhtawar, Rahman Hamid, Ul Islam Shams, Hussain Majeed Afraz, Ahmad Irshad
Department of Mathematics and Computer Science, Faculty of Science, Menoufia University, Shebin El Kom, Menofia, 32511, Egypt.
Department of Mathematics, Air University, Islamabad, 44000, Pakistan.
Sci Rep. 2024 Aug 5;14(1):18049. doi: 10.1038/s41598-024-66895-0.
This study presents a computational analysis of fluid flow characteristics around two staggered arranged square cylinders using the Lattice Boltzmann Method (LBM). With Reynolds number (Re) fixed at 200, numerical simulations explore the influence of varying gap ratios (G) ranging from 0 to 10 times the cylinder size. Emphasis is placed on understanding the impact of cylinders spacing on flow structure mechanisms and induced forces. Investigation of fluid flow parameters includes vorticity behavior, pressure streamlines, and variations in drag and lift coefficients alongside the Strouhal number under different values of G. From the results, four distinct flow patterns emerge: single bluff body flow, flip flopping flow, modulated synchronized flow, and synchronized flow, each exhibiting unique characteristics. This study reveals the strong dependence of fluid forces on G, with low spacing values leading to complex vortex structures and fluctuating forces influenced by jet flow effects. At higher spacing values, proximity effects between cylinders diminish, resulting in a smoother periodic flow. The Strouhal number, average drag force and the rms values of drag and lift force coefficients vary abruptly at narrow gaps and become smooth at higher gap ratios. Unlike the tandem and side-by-side arrangements the staggered cylinders arrangement is found to have significant impact on the pressure variations around both cylinders. Overall, this research could contribute to a comprehensive understanding of staggered cylinder arrangements and their implications for engineering applications.
本研究采用格子玻尔兹曼方法（LBM）对两个交错排列的方形圆柱体周围的流体流动特性进行了计算分析。在雷诺数（Re）固定为200的情况下，数值模拟探究了间隙比（G）在0至10倍圆柱体尺寸范围内变化的影响。重点在于理解圆柱体间距对流动结构机制和诱导力的影响。对流体流动参数的研究包括涡度行为、压力流线，以及在不同G值下阻力和升力系数的变化以及斯特劳哈尔数。结果显示出现了四种不同的流动模式：单个钝体流动、交替流动、调制同步流动和同步流动，每种模式都具有独特的特征。本研究揭示了流体力对G的强烈依赖性，较小的间距值会导致复杂的涡旋结构以及受射流效应影响的波动作用力。在较大的间距值时，圆柱体之间的邻近效应减弱，从而形成更平滑的周期性流动。斯特劳哈尔数、平均阻力以及阻力和升力系数的均方根值在狭窄间隙处会突然变化，而在较大间隙比时则变得平滑。与串联和并排排列不同，交错圆柱体排列对两个圆柱体周围的压力变化有显著影响。总体而言，本研究有助于全面理解交错圆柱体排列及其在工程应用中的意义。
