Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
CONJUGATED HEAT TRANSFER WITH SLIP FLOW IN MICROCHANNELS: SINGLE DOMAIN INTEGRAL TRANSFORMS WITH ENHANCED CONVERGENCE
Submission Author:
Diego Knupp , RJ , Brazil
Co-Authors:
Diego Knupp, Fabricio Mascouto, Luiz A. S. Abreu, Carolina Palma Naveira Cotta, Renato Machado Cotta
Presenter: Luiz A. S. Abreu
doi://10.26678/ABCM.ENCIT2016.CIT2016-0228
Abstract
Several recent contributions have been published addressing the formulation and solution of heat and fluid flow problems under circumstances found in miniaturized thermomechanical equipment. Among several model propositions to describe the fluid flow and heat transfer in the microscale, we may highlight the consideration of slip flow in opposition to the classical no-slip condition and the formulation of conjugated conduction-convection heat transfer problems to accurately describe the effects of the solid channel walls on the thermal process. Aiming at unifying a hybrid analytical-numerical approach for conjugated problems, the authors have recently proposed and advanced the analysis of such class of problems through a combination of a single domain formulation strategy and integral transforms, by combining the energy and diffusion equations into a single problem, for the whole spatial domain. In this case, by making use of space variable coefficients, with abrupt transitions occurring at fluid-wall interface, the mathematical model is fed with the information concerning the two original domains of the problem, and then the Generalized Integral Transform Technique is employed for the solution of the resulting mathematical problem. More recently, a convergence acceleration scheme known as integral balance has been successfully employed to derive improved expansion expressions, allowing for the analysis of multi-scale problems. The present paper is aimed at advancing this established solution methodology in order to tackle the conjugated heat transfer problem involving incompressible laminar gas flow in cylindrical microchannels, within the rage of validity of the slip flow regime. For validation purposes, and in order to provide a critical analysis, a test problem on steady or quasi-steady state hydrodynamically fully developed and thermally developing convection is chosen and also solved through a dedicated finite difference code.
Keywords
Conjugated heat transfer, Slip Flow, Cylindrical microchannels, Integral Transforms, Integral balance
