Thermal and friction characteristics of laminar flow through rectangular and square ducts with transverse ribs and wire coil inserts

Sujoy Kumar Saha

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

The heat transfer and the pressure drop characteristics of laminar flow of viscous oil (195 < Pr < 525) through rectangular and square ducts with internal transverse rib turbulators on two opposite surfaces of the ducts and with wire coil inserts have been studied experimentally. Circular duct has also been used. The transverse ribs in combination with wire coil inserts have been found to perform better than either ribs or wire coil inserts acting alone. The heat transfer and the pressure drop measurements have been taken in separate test sections. Heat transfer tests were carried out in electrically heated stainless steel ducts incorporating uniform wall heat flux boundary conditions. Pressure drop tests were carried out in acrylic ducts. The flow friction and thermal characteristics are governed by duct aspect ratio, coil helix angle and wire diameter of the coil, rib height and rib spacing, Reynolds number and Prandtl number. Correlations developed for friction factor and Nusselt number have predicted the experimental data satisfactorily. The performance of the geometry under investigation has been evaluated. It has been found that on the basis of constant pumping power, up to fifty per cent heat duty increase occurs for the combined ribs and wire coil inserts case compared to the individual ribs and wire coil inserts cases in the measured experimental parameters space. On the constant heat duty basis, the pumping power has been reduced up to forty per cent for the combined enhancement geometry than the individual enhancement geometries. © 2009 Elsevier Inc. All rights reserved.
Original languageEnglish
Pages (from-to)63 - 72
Number of pages10
JournalExperimental Thermal and Fluid Science
Volume34
Issue number1
DOIs
Publication statusPublished - Jan 2010
Externally publishedYes

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Nuclear Energy and Engineering
  • Aerospace Engineering
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this