W. Abbasi, Muhammad Ehsan, H. Rahman, Zia Uddin, Mohammad Mehedi Hassan, Kashif Saleem
{"title":"Analysis of the wake mechanism in external flow around tandem bluff bodies with different aspect ratios","authors":"W. Abbasi, Muhammad Ehsan, H. Rahman, Zia Uddin, Mohammad Mehedi Hassan, Kashif Saleem","doi":"10.3389/fmech.2024.1341618","DOIUrl":null,"url":null,"abstract":"The interaction mechanism of external flow with two inline rectangular cylinders having different aspect ratios under the impact of gap spacing (G) is the subject of this research. The gap spacing between the cylinders was varied from 0.25 to 20 times their size. Both cylinders were vertically mounted, with the first having a higher aspect ratio than the second. The results revealed five distinct flow patterns under the influence of G: single slender body, shear layer reattachment, intermittent shedding, binary vortex street, and single-row vortex street. The mean pressure on both cylinders was found to vary due to changes in flow patterns. Both cylinders bore the same shedding frequency but had different pressure variations. The second cylinder placed in the wake of first experienced negative average drag force for some spacing values, while the first cylinder had positive average drag values for all chosen G. Due to the change in flow pattern from shear layer reattachment to intermittent shedding flow, the negative drag force on the second cylinder jumped to a positive drag. It was also observed that the rms values of drag and lift force coefficients, as well as their amplitudes for the second cylinder, were mostly higher than corresponding values for the first cylinder at all selected G. This study revealed that G = 4 and 8 are the critical gap spacing values due to sudden changes in fluid force parameters.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Mechanical Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3389/fmech.2024.1341618","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The interaction mechanism of external flow with two inline rectangular cylinders having different aspect ratios under the impact of gap spacing (G) is the subject of this research. The gap spacing between the cylinders was varied from 0.25 to 20 times their size. Both cylinders were vertically mounted, with the first having a higher aspect ratio than the second. The results revealed five distinct flow patterns under the influence of G: single slender body, shear layer reattachment, intermittent shedding, binary vortex street, and single-row vortex street. The mean pressure on both cylinders was found to vary due to changes in flow patterns. Both cylinders bore the same shedding frequency but had different pressure variations. The second cylinder placed in the wake of first experienced negative average drag force for some spacing values, while the first cylinder had positive average drag values for all chosen G. Due to the change in flow pattern from shear layer reattachment to intermittent shedding flow, the negative drag force on the second cylinder jumped to a positive drag. It was also observed that the rms values of drag and lift force coefficients, as well as their amplitudes for the second cylinder, were mostly higher than corresponding values for the first cylinder at all selected G. This study revealed that G = 4 and 8 are the critical gap spacing values due to sudden changes in fluid force parameters.
本研究的主题是在间隙间距(G)的影响下,外部流体与两个具有不同长宽比的直列矩形圆柱体的相互作用机制。圆柱体之间的间隙间距从 0.25 到 20 倍不等。两个圆柱体都垂直安装,第一个圆柱体的长宽比高于第二个圆柱体。结果表明,在 G 的影响下,有五种不同的流动模式:单一细长体、剪切层重新附着、间歇脱落、二元涡街和单排涡街。由于流动模式的变化,两个圆柱体上的平均压力也发生了变化。两个气缸的脱落频率相同,但压力变化不同。由于流型从剪切层重新附着变为间歇脱落流,第二个圆筒上的负阻力跃升为正阻力。研究还发现,在所有选定的 G 值下,第二个圆筒的阻力和升力系数的均方根值及其振幅大多高于第一个圆筒的相应值。