Interaction between mean flow and thermo-hydraulic behaviour in inclined louvered fins.

*(English)*Zbl 1209.80026Summary: In this study the inclined louvered fin, a hybrid fin design based on the slit fin and louvered fin design is considered. The goal of the research program is to investigate the interaction between the flow behaviour (flow deflection and transition to unsteady flow) and the thermo-hydraulics of the fin design. This approach was selected in order to reveal the flow physics behind the transitions found in the thermo-hydraulic data. Through flow visualization (dye injection in a water tunnel) the flow deflection and transition to unsteady flow was studied in different configurations and for varying Reynolds number. The flow deflection was quantified through the ‘fin angle alignment factor’. Validated CFD simulations were used to further explore flow behaviour. In parallel, wind tunnel measurements were performed measuring the local heat transfer coefficients for the different louvers and the overall pressure drop. The impact of the fin pitch, fin angle and Reynolds number were studied. A comparison of both local and global parameters to the observed flow behaviour revealed the strong coupling between the flow and the thermo-hydraulics showing evidence of boundary layer driven flow.

##### MSC:

80A20 | Heat and mass transfer, heat flow (MSC2010) |

76M12 | Finite volume methods applied to problems in fluid mechanics |

PDF
BibTeX
XML
Cite

\textit{C. T'Joen} et al., Int. J. Heat Mass Transfer 54, No. 4, 826--837 (2011; Zbl 1209.80026)

Full Text:
DOI

**OpenURL**

##### References:

[1] | Shah, R. K.; Sekulic, D. P.: Fundamentals of heat exchanger design, (2003) |

[2] | Bergles, A. E.: Exhft for fourth generation heat transfer technology, Exp. therm. Fluid sci. 26, 335-344 (2002) |

[3] | Romero-Méndez, R.; Sen, M.; Yang, K. T.; Mccclain, R.: Effect of fin spacing on convection in a plate fin and tube heat exchanger, Int. J. Heat mass transfer 43, 39-51 (2000) |

[4] | Mon, M. S.; Gross, U.: Numerical study of fin-spacing effects in annular-finned tube heat exchangers, Int. J. Heat mass transfer 47, 1953-1964 (2004) |

[5] | Sedney, R.: A survey of the effects of small protuberances on boundary-layer flows, Aiaa j. 11, 782-792 (1973) |

[6] | Jacobi, A. M.; Shah, R. K.: Heat transfer surface enhancement through the use of longitudinal vortices – A review of recent progress, Exp. therm. Fluid sci. 11, 295-309 (1995) |

[7] | Joardar, A.; Jacobi, A. M.: Heat transfer enhancement by winglet type vortex generator arrays in compact plain-fin-and-tube heat exchangers, Int. J. Refrig. 31, 87-97 (2008) |

[8] | O’brien, J. E.; Sohal, M. S.: Heat transfer enhancement for finned-tube heat exchangers with winglets, J. heat transfer trans. ASME 127, 171-178 (2005) |

[9] | H. Ge, A.M. Jacobi, J.C. Dutton, Air side heat transfer enhancement in offset-strip fin array using delta wing vortex generators – ACRC TR-205, Technical report, ACRC – University of Illinois, 2005. |

[10] | Joardar, A.; Jacobi, A. M.: Impact of leading edge delta-wing vortex generators on the thermal performance of a flat tube, louvered-fin compact heat exchanger, Int. J. Heat mass transfer 48, 1480-1493 (2005) |

[11] | Metwally, H. M.; Manglik, R. M.: Enhanced heat transfer due to curvature-induced lateral vortices in laminar flows in sinusoidal corrugated-plate channels, Int. J. Heat mass transfer 47, 2283-2292 (2004) |

[12] | Rush, T. A.; Newell, T. A.; Jacobi, A. M.: An experimental study of flow and heat transfer in sinusoidal wavy passages, Int. J. Heat mass transfer 42, 1541-1553 (1999) |

[13] | T’joen, C.; Steeman, H. J.; Willockx, A.; De Paepe, M.: Determination of heat transfer and friction characteristics of an adapted inclined louvered fin, Exp. therm. Fluid sci. 30, 319-327 (2006) |

[14] | Manglik, R. M.; Bergles, A. E.: Heat-transfer and pressure-drop correlations for the rectangular offset strip fin compact heat-exchanger, Exp. therm. Fluid sci. 10, 171-180 (1995) |

[15] | Wang, C. C.; Lee, W. S.; Sheu, W. J.: A comparative study of compact enhanced fin-and-tube heat exchangers, Int. J. Heat mass transfer 44, 3565-3573 (2001) |

[16] | Wang, C. C.; Lee, C. J.; Chang, C. T.; Lin, S. P.: Heat transfer and friction correlation for compact louvered fin-and-tube heat exchangers, Int. J. Heat mass transfer 42, 1945-1956 (1999) |

[17] | Dejong, N. C.; Jacobi, A. M.: An experimental study of flow and heat transfer in parallel-plate arrays: local, row-by-row and surface average behavior, Int. J. Heat mass transfer 40, 1365-1378 (1997) |

[18] | Dejong, N. C.; Jacobi, A. M.: Localized flow and heat transfer interactions in louvered-fin arrays, Int. J. Heat mass transfer 46, 443-455 (2003) |

[19] | Tafti, D. K.; Zhang, X.: Geometry effects on flow transition in multilouvered fins – onset, propagation, and characteristic frequencies, Int. J. Heat mass transfer 44, 4195-4210 (2001) · Zbl 1091.76508 |

[20] | Cui, J.; Tafti, D. K.: Computations of flow and heat transfer in a three dimensional multilouvered fin geometry, Int. J. Heat mass transfer 45, 5007-5023 (2002) · Zbl 1032.76612 |

[21] | Achaichia, A.; Cowell, T. A.: Heat transfer and pressure drop characteristics of flat tube and louvered plate fin surfaces, Exp. therm. Fluid sci. 1, 147-157 (1988) |

[22] | Zhang, X.; Tafti, D. K.: Flow efficiency in multi-louvered fins, Int. J. Heat mass transfer 46, 1737-1750 (2003) |

[23] | Lyman, A. C.; Stephan, R. A.; Thole, K. A.; Zhang, L. W.; Memory, S. B.: Scaling of heat transfer coefficients along louvered fins, Exp. therm. Fluid sci. 26, 547-563 (2002) |

[24] | Tanaka, T.; Itoh, M.; Kudoh, M.; Tomita, A.: Improvement of compact heat exchangers with inclined louvered fins, Bull. JSME 27, 219-226 (1984) |

[25] | Jacobi, A. M.; Shah, R. K.: Air side flow and heat transfer in compact heat exchangers: a discussion of enhancement mechanisms, Heat transfer eng. 19, 29-41 (1998) |

[26] | Shah, R. K.; Heikal, M. R.; Thonon, B.; Tochon, P.: Progress in the numerical analysis of compact heat exchangers, Adv. heat transfer 34, 363-443 (2001) |

[27] | C. T’Joen, A. Willockx, H.J. Steeman, M. De Paepe, Thermo-hydraulic characteristics of inclined louvered fins, in: Proceedings of the 6th International Conference on Enhanced, Compact and Ultra-Compact Heat Exchangers, Potsdam, Germany, 16 – 21 September 2007. |

[28] | Dejong, N. C.; Jacobi, A. M.: Flow, heat transfer and pressure drop in the near-wall region of louvered-fin arrays, Exp. therm. Fluid sci. 27, 237-250 (2003) |

[29] | T’joen, C.; Jacobi, A. M.; De Paepe, M.: Flow visualization in inclined louvered fins, Exp. therm. Fluid sci. 33, 664-674 (2009) |

[30] | T’joen, C.; Huisseune, H.; Willockx, A.; Canière, H.; De Paepe, M.: Combined experimental and numerical flow field study of inclined louvered fins, Heat transfer eng. 32, 176-188 (2011) · Zbl 1209.80026 |

[31] | C. T’Joen, Thermo-hydraulic study of inclined louvered fins, Ph.D. thesis, Ghent University-UGent, Belgium, 2008. Available from: <http://hdl.handle.net/1854/LU-528875>. |

[32] | Mehta, R. D.; Bradshaw, P.: Design rules for small low speed wind tunnels, Aeronaut. J. R. aeronaut. Soc. 73, 443-449 (1979) |

[33] | Kays, W. M.; London, A. L.: Compact heat exchangers, (1984) |

[34] | Shah, R. K.; London, A. L.: Laminar flow forced convection in ducts, (1978) |

[35] | Zhang, X.; Tafti, D. K.: Classification and effects of thermal wakes on heat transfer in multilouvered fins, Int. J. Heat mass transfer 44, 2461-2473 (2001) · Zbl 0983.76500 |

[36] | Moffat, R. J.: What’s new in convective heat transfer?, Int. J. Heat fluid flow 19, 90-101 (1998) |

[37] | Moffat, R. J.: Describing the uncertainties in experimental results, Exp. therm. Fluid sci. 1, 3-17 (1988) |

[38] | Kadoya, K.; Matsunaga, N.; Nagashima, A.: Viscosity and thermal-conductivity of dry air in the gaseous-phase, J. phys. Chem. ref. Data 14, No. 4, 947-970 (1985) |

[39] | Springer, M. E.; Thole, K. A.: Experimental design for flowfield studies in louvered fins, Exp. therm. Fluid sci. 18, 258-269 (1998) |

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.