Effect of Tube Diameter on Natural Convection Heat Transfer in Circular Vertical Pipe Flows

A numerical study of convective heat transfer from a uniformly heated vertical tube under constant wall heat flux has been investigated. The effect of different sections (restrictions) diameter placed at the exit of the tube on temperature, velocity and Nusselt number were examined. The restrictions were circular tubes having same length but different diameters. A set of governing equations i. e. continuity equation (mass conservation), momentum conservation, and energy conservation equations were non- dimensionalized and then solved using the Finite Difference Method. Discretized finite difference equations together with their boundary conditions were solved using the R-software and matlab Analysis of the effect of diameter on temperature, velocity profiles and Nusselt number for different diameters was done. The results obtained were presented graphically and discussed.