Network modelling of unsteady natural convection flow over a vertical plate submitted to surface temperature oscillation

Abstract

Purpose

The unsteady natural convection flow of a viscous dissipative fluid along a semi‐infinite vertical plate subjected to periodic surface temperature oscillation is investigated.

Design/methodology/approach

An electrical‐network model based on the Network Simulation Method is developed to solve the governing equations. The accuracy and effectiveness of the method are demonstrated.

Findings

The increasing of the viscous dissipation and the decreasing in the Prandtl number lead to a decrease in Nusselt number and an increase in the local skin‐friction. Also, it is found that the oscillations of the Nusselt number and of the local skin‐friction depend on the frequency and amplitude of the oscillating surface temperature. For Pr = 1,000 and ε = 0.005 (realistic case) the effect of the viscous dissipation is appreciable at large distances from the leading edge.

Research limitations/implications

The inclusion of viscous dissipation in the energy equation, except of the theoretical interest, has applications in very special cases, for example, gases at very low temperature and also for high Prandtl number liquids.

Originality/value

The influence of the non‐uniformity of wall temperature on the heat transfer by natural convection along of the plate together with the viscous dissipation of the fluid are analysed by means of a new numerical technique based on the electrical analogy.

Citation

Zueco, J. (2009), "Network modelling of unsteady natural convection flow over a vertical plate submitted to surface temperature oscillation", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 19 No. 3/4, pp. 285-302. https://doi.org/10.1108/09615530910938290