Effects of temperature dependent fluid properties and variable Prandtl number on the transient convective flow due to a porous rotating disk

M. S. Alam, S. M Chapal Hossain, M. M. Rahman

Research output: Contribution to journalArticle

8 Citations (Scopus)


In this paper we have studied the effects of temperature dependent fluid properties such as density, viscosity and thermal conductivity and variable Prandtl number on unsteady convective heat transfer flow over a porous rotating disk. Using similarity transformations we reduce the governing nonlinear partial differential equations for flow and heat transfer into a system of ordinary differential equations which are then solved numerically by applying Nachtsheim-Swigert shooting iteration technique along with sixth-order Runge-Kutta integration scheme. Comparison with previously published work for steady case of the problem were performed and found to be in very good agreement. The obtained numerical results show that the rate of heat transfer in a fluid of constant properties is higher than in a fluid of variable properties. The results further show that consideration of Prandtl number as constant within the boundary layer for variable fluid properties lead unrealistic results. Therefore, modeling thermal boundary layers with temperature dependent fluid properties Prandtl number must treated as variable inside the boundary layer.

Original languageEnglish
Pages (from-to)2439-2451
Number of pages13
Issue number10
Publication statusPublished - 2014



  • Heat transfer
  • Rotating disk
  • Unsteady flow
  • Variable fluid properties
  • Variable Prandtl number

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Condensed Matter Physics

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