The major heat transfer takes by two modes i.e. by conduction followed by convection. Heat transfer through the solid to the surface of the solid takes place through conduction where as from the surface to the surroundings takes place by convection. Further heat transfer may be by natural convectionor by forced convection. The rate of heat transfer from a surface at a temperature ‘Ts’ to the surrounding medium at ‘To’ is given by the Newton’s law of cooling …show more content…
The channel had a cross-sectional area of 250-100 mm2. Range of Reynolds number 13,500–42,000 covered by them, the clearance ratio (C/H) 0, 0.33 and 1, the inter-fin spacing ratio (Sy/D) 1.208, 1.524, 1.944 and 3.417. Correlation equations were developed for the heat transfer, friction factor and enhancement efficiency. The experimental results showed that the use of the square pin fins may lead to heat transfer enhancement. Enhancement efficiencies varied between 1.1 and 1.9 depending on the clearance ratio and inter-fin spacing ratio. Both lower clearance ratio and lower inter-fin spacing ratio and comparatively lower Reynolds numbers are suggested for higher thermal performance. In this study, the overall heat transfer, friction factor and the effect of the various design parameters on the heat transfer and friction factor for the heat exchanger equipped with square cross-sectional perforated pin fins were investigated experimentally. The effects of the flow and geometrical parameters on the heat transfer and friction characteristics were determined, and the enhancement efficiency correlations have been obtained The average Nusselt number calculated on the basis of projected area increased with decreasing clearance ratio and inter-fin spacing ratio. The friction