Abstract
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 language | English |
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Pages (from-to) | 2439-2451 |
Number of pages | 13 |
Journal | Meccanica |
Volume | 49 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2014 |
Keywords
- Heat transfer
- Rotating disk
- Unsteady flow
- Variable Prandtl number
- Variable fluid properties
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering