Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2754

Full Length Research Paper

Heat transfer and entropy generation in a pipe flow with temperature dependent viscosity and convective cooling

  M. S. Tshehla1*, O. D. Makinde2 and G. E. Okecha3
    1Department of Mathematics, Faculty of Military Science, University of Stellenbosch, P/Bag X2, Saldanha, 7395, South Africa. 2Faculty of Engineering, Cape Peninsula University of Technology, P. O. Box 1906, Bellville 7535, South Africa. 3Department of Mathematics and Applied Mathematics, University of Fort Hare, P/Bag X1314, Alice 5700, South Africa.  
Email: [email protected]

  •  Accepted: 11 November 2010
  •  Published: 31 December 2010




The second law analysis is performed to study the entropy generation rate in a variable viscosity liquid flowing steadily through a cylindrical pipe with convective cooling at the pipe surface. The system is assumed to exchange heat with the ambient following Newton’s cooling law and the fluid viscosity model varies as an inverse linear function of temperature. The analytical expressions for fluid velocity and temperature that were derived essentially expedite the expressions for volumetric entropy generation of numbers, irreversibility distribution ratio and the Bejan number in the flow field.


Key words: Pipe flow, variable viscosity, convective cooling, irreversibility analysis.