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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

INFLUENCE OF TURBULENCE INTENSITY ON HEAT TRANSFER AND PRESSURE DROP IN COMPACT HEAT EXCHANGERS

Get access (open in a dialog) DOI: 10.1615/IHTC8.1190
pages 2739-2744

要約

Results of experimental investigations of the influence of turbulence intensity on heat transfer and pressure drop in a single row and in bundles of three to five rows of plain tubes are presented. The vertically arranged tubes in the bundle were heated by saturated steam, condensing inside, and cooled outside by crossflowing air. The isotropic turbulence intensity in the entrance cross section was varied between 0.8% and 25% by means of grids. Bundles with in-line and staggered tube arrangements were investigated. Air-side Reynolds numbers ranged from 2×104 to 1.5×105 . It turned out that the enhancement of heat transfer coefficients is due to an increase of the turbulence level. The drag coefficient for the bundle is almost independent of the inlet turbulence intensity in a wide range of the Reynolds number. The use of turbulence grids therefore lead to higher efficiencies of the heat exchangers.