Evaluation of Convective Heat Transfer Coefficient of Air Flowing Through an Inclined Circular Duct
Volume. 7, Issue. 9, September - 2018, IJERT
7 Pages Posted: 22 Oct 2018
Date Written: September 22, 2018
Circular duct has various applications - pipelines, HVAC, and refrigeration - as it can withstand more pressure drop than non-circular duct. Generally, fluids are forced through the pipes for various purposes. So, Pipes are generally required to be installed at various positions in order to minimize or maximize heat loss, regulate the flow and for the proper utilization of space to meet the design considerations. When fluids are forced through pipes, Heat transfer follows forced convection and the convective heat transfer coefficient plays pivotal role in the design considerations. Hence, it is must to understand the influence of factors such as inclination of pipe, velocity of fluid, and temperature gradient on convective heat transfer coefficient. Literature survey showed little research on effect of those factors in convective heat transfer coefficient. The main purpose of this work is to find out the nature of convective heat transfer coefficient when the air is forced through the copper pipe at different inclination and velocity at constant heat input. Different temperature at various points and the manometer reading were noted and were used to calculate Reynolds number, Prandtl number, and Nusselts number to find out convective heat transfer coefficient. The result obtained was plotted to observe the nature of heat transfer coefficient. The graph showed that heat transfer coefficient rises to its peak at 900 inclination of the duct for velocity of 12 m/s and falls to minimum value at 300 inclination of the duct for velocity of 8.38 m/s. It is also found that heat transfer coefficient is linearly dependent on velocity and is also influenced by inclination of the duct.
Keywords: Fluids, Convection, Convective Heat Transfer Coefficient, Reynolds Number, Prandtl Number, Nusselts Number
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