Steady separated flow around a pair of identical square cylinders in tandem array at low Reynolds numbers.

*(English)*Zbl 07124557Summary: The steady separated flow past two identical square cylinders in tandem arrangement is studied numerically. For a Reynolds number of 40, flow features are investigated for varied centre-to-centre distance, \(S\) between cylinders. The range of normalized spacing, \(\frac{S}{D}\) is 2–30 where \(D\) denotes edge length of cylinders. Based on separation topology, four distinct flow regimes are identified. In regime I, the cylinders are closely spaced and gap between the cylinders is occupied by a pair of eddies and no wake forms behind the upstream cylinder. In regimes I and II, the cylinders are bridged by zero streamlines enveloping the gap flow. Thus, the cylinders along with the enclosed fluid, act as a single obstacle. Regime II forms as a manifestation of the first bifurcation of flow; the twin eddies in the gap split into four vortices. In regime III, the second bifurcation of flow occurs. The gap recirculation with four eddies splits; the first pair of counterrotating eddies contribute to wake of the upstream cylinder whereas the other pair adheres as a tiny vortical structure to the front part of downstream cylinder. In regime IV, separation topology is characterized by individual cylinder wakes. Four separation topologies, one corresponding to each regime, are proposed. The maximum width of the recirculation zone/wake of the upstream cylinder always exceeds the width of its downstream counterpart signifying higher drag for the former. For most of regime I, the downstream cylinder acts as a streamlined body.

##### MSC:

76 | Fluid mechanics |

##### Keywords:

tandem square cylinders; stabilized finite-element; steady flow; regimes of flow; surface pressure; pressure drag
PDF
BibTeX
XML
Cite

\textit{D. Kumar} et al., Comput. Fluids 191, Article ID 104244, 16 p. (2019; Zbl 07124557)

Full Text:
DOI

##### References:

[1] | Bao, Y.; Wu, Q.; Zhou, D., Numerical investigation of flow around an inline square cylinder array with different spacing ratios, Comput Fluids, 55, 118-131 (2012) · Zbl 1291.76196 |

[2] | Bearman, P. W.; Wadcock, A. J., The interaction between a pair of circular cylinders normal to a stream, J Fluid Mech, 61, 499-511 (1973) |

[3] | Chatterjee, D.; Mondal, B., Forced convection heat transfer from tandem square cylinders for various spacing ratios, Numer Heat Transf Part A, 61, 5, 381-400 (2012) |

[4] | Ehsan, I.; Mohammad, S.; Reza, N. M.; Ali, J.; Tashnizi, E. S., Power-law fluid flow passing two square cylinders in tandem arrangement, J Fluids Eng, 135, 6, 061101 (2013) |

[5] | Etminan, A.; Moosavi, M.; Ghaedsharafi, N., Determination of flow configurations and fluid forces acting on two tandem square cylinders in cross-flow and its wake patterns, Int J Mech, 5, 63-74 (2011) |

[6] | Fornberg, B., Steady viscous flow past a circular cylinder up to Reynolds number 600, J Comput Phys, 61, 297-320 (1985) · Zbl 0576.76026 |

[7] | Hunt, J. C.R.; Abell, C. J.; Peterka, J. A.; Woo, H., Kinematical studies of the flows around free or surface-mounted obstacles; applying topology to flow visualization, J Fluid Mech, 86, 1, 179-200 (1978) |

[8] | Ishigai, S.; Nishikawa, E.; Nishimura, K.; Cho, K., Experimental study on structure of gas flow in tube banks with tube axes normal to flow: Part 1, Karman vortex flow from two tubes at various spacings, Bull JSME, 15, 86, 949-956 (1972) |

[9] | Kostic, Z. G.; Oka, S. N., Fluid flow and heat transfer with two cylinders in cross flow, Int J Heat Mass Transf, 15, 279-299 (1972) |

[10] | Kumar, D.; Sourav, K.; Sen, S.; Yadav, P. K., Steady separation of flow from an inclined square cylinder with sharp and rounded base, Comput Fluids, 171, 29-40 (2018) · Zbl 1410.76183 |

[11] | Meneghini, J. R.; Saltara, F.; Siqueira, C. L.R.; Ferrari, J. A., Numerical simulation of flow interference between two circular cylinders in tandem and side-by-side arrangements, J Fluids Struct, 15, 327-350 (2001) |

[12] | Mittal, S.; Kumar, V.; Raghuvanshi, A., Unsteady incompressible flows past two cylinders in tandem and staggered arrangements, Int J Numer Methods Fluids, 25, 1315-1344 (1997) · Zbl 0909.76050 |

[13] | Miyazaki, T.; Hasimoto, H., Separation of creeping flow past two circular cylinders, J Phys Soc Jpn, 49, 4, 1611-1618 (1980) |

[14] | Nejat, A.; Abdollahi, V.; Vahidkhah, K., Lattice Boltzmann simulation of non-Newtonian flows past confined cylinders, J Non-Newton Fluid Mech, 166, 12-13, 689-697 (2011) · Zbl 1282.76037 |

[15] | Patil, R. C.; Bharti, R. P.; Chhabra, R. P., Steady flow of power-law fluids over a pair of cylinders in tandem arrangement, Ind Eng Chem Res, 47, 5, 1660-1683 (2008) |

[16] | Roshko, A., Perspectives on bluff body aerodynamics, J Wind Eng Ind Eng, 49, 79-100 (1993) |

[17] | Sen, S.; Mittal, S.; Biswas, G., Steady separated flow past a circular cylinder at low Reynolds numbers, J Fluid Mech, 611, 89-110 (2009) · Zbl 1156.76381 |

[18] | Sen, S.; Mittal, S.; Biswas, G., Flow past a square cylinder at low Reynolds numbers, Int J Numer Methods Fluids, 67, 9, 1160-1174 (2011) · Zbl 1426.76303 |

[19] | Sharman, B.; Lien, F. S.; Davidson, L.; Norberg, C., Numerical predictions of low Reynolds number flows over two tandem circular cylinders, Int J Numer Methods Fluids, 47, 423-447 (2005) · Zbl 1085.76044 |

[20] | Shyam, R.; Chhabra, R. P., Effect of prandtl number on heat transfer from tandem square cylinders immersed in power-law fluids in the low Reynolds number regime, Int J Heat Mass Transf, 57, 2, 742-755 (2013) |

[21] | Singha, S.; Sinhamahapatra, K. P., High-resolution numerical simulation of low Reynolds number incompressible flow about two cylinders in tandem, J Fluids Eng, 132, 1, 011101 (2010) |

[22] | Sohankar, A., A numerical investigation of the flow over a pair of identical square cylinders in a tandem arrangement, Int J Numer Methods Fluids, 70, 10, 1244-1257 (2011) · Zbl 1412.65156 |

[23] | Sohankar, A.; Etminan, A., Forced convection heat transfer from tandem square cylinders in cross flow at low Reynolds numbers, Int J Numer Methods Fluids, 60, 7, 733-751 (2009) · Zbl 1369.76010 |

[24] | Sumner, D., Two circular cylinders in cross-flow: a review, J Fluids Struct, 26, 6, 849-899 (2010) |

[25] | Tatsuno, M., Steady flows around two cylinders at low Reynolds numbers, Fluid Dyn Res, 5, 1, 49-60 (1989) |

[26] | Tatsutani, K.; Devarakonda, R.; Humphrey, J. A.C., Unsteady flow and heat transfer for cylinder pairs in a channel, Int J Heat Mass Transf, 36, 13, 3311-3328 (1993) |

[27] | Tezduyar, T. E.; Mittal, S.; Ray, S. E.; Shih, R., Incompressible flow computations with stabilized bilinear and linear equal-order-interpolation velocity pressure elements, Comput Methods Appl Mech Eng, 95, 221-242 (1992) · Zbl 0756.76048 |

[28] | Vakil, A.; Green, S. I., Numerical study of two-dimensional circular cylinders in tandem at moderate Reynolds numbers, J Fluids Eng, 135, 7, 071204 (2013) |

[29] | Zdravkovich, M. M., Review of flow interference between two circular cylinders in various arrangements, J Fluids Eng, 99, 4, 618-633 (1977) |

[30] | Zdravkovich, M. M., The effects of interference between circular cylinders in cross flow, J Fluids Struct, 1, 2, 239-261 (1987) |

[31] | Zhou, Y.; Alam, M. M., Wake of two interacting circular cylinders: a review, Int J Heat Fluid Flow, 62, 510-537 (2016) |

This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.