AN ANALYSIS ON FULLY-DEVELOPED LAMINAR FLUID-FLOW AND HEAT-TRANSFER IN CONCENTRIC ANNULI WITH MOVING CORES

An analysis is made on the momentum and heat transfer between a fully developed laminar fluid flow and a moving core of fluid or solid body in an annular geometry. The annulus is concentric and both the wall surfaces are smooth. The heating condition is a uniform heat flux at either or both of the surfaces. The two fundamental solutions are obtained and the solutions for the inner and outer tubes for any heat flux ratio are then obtained through influence coefficients, which are evaluated from the fundamental solution from the definition. The effects of various parameters such as the relative velocity, the ratio, etc. on friction factor and Nusselt number are investigated.