ENTROPY GENERATION IN THERMALLY FULLY DEVELOPED ELECTRO-OSMOTIC FLOW IN CIRCULAR MICROTUBES

摘要

An analysis has been provided for the entropy generation in thermally fully developed electro-osmotically generated flow in a circular microtube in terms of Brinkman number, Peclet number, relative duct radius, dimensionless joule heating parameter, dimensionless viscous heating parameter as well as physical properties of the fluid under imposed constant wall heat flux boundary condition. Such a flow is established not by an imposed pressure gradient, but by a voltage potential gradient along the length of the tube. The momentum and energy equations are solved to get the velocity and temperature distributions and the exact solution for the dimensionless entropy generation number have been determined analytically. This analysis assumes no pressure-driven component to the velocity field and constant fluid properties. Five different variables namely, (i) dimensionless joule heating parameter, (ii) dimensionless viscous heating parameter, (iii) relative duct radius, (iv) Peclet number and (v) Brinkman number have been identified from the dimensionless entropy generation number equation. Results for dimensionless entropy generation number, Bejan number, Irreversibility ratio and entropy generation are presented.