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ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

HEAT TRANSFER ENHANCEMENT OF FINNED OVAL TUBES WITH PUNCHED WING-TYPE LONGITUDINAL VORTEX GENERATORS

Get access (open in a dialog) DOI: 10.1615/IHTC11.1950
pages 351-356

Résumé

Heat transfer enhancement (HTE) and flow loss penalty (FLP) in a high performance finned oval tube (FOT) heat exchanger element with punched delta-winglet pairs (DWP) are studied numerically by calculating the 3D flows and conjugate heat transfer for thermally and hydrodynamically developing laminar flow (100<Re = u 0H/ν )< 500). Finite-Volume Method with the SIMPLEC-Algorithm and a co-located arrangement of the dependent variables are employed. Body-fitted grids are used to satisfy exactly the thermal and hydrodynamical boundary conditions. The conjugate heat transfer is realized by iterations of convection in the flow field and conduction in the fin. The area ratio of one DWP to fin is 1.73%. Flow and temperature fields, vortex formation, local and global heat transfer and flow loss are presented. Performance of FOTs with up to four in-line or staggered DWPs are evaluated. Staggered arrangement of the winglets intensifies energy transport cross to the main flow. Compared to an FOT without Winglets, an FOT with four staggered DWPs can save about 50% of transfer area according to the VG1 criterion.