Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux

Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux

The article addresses the extended Graetz–Nusselt problem in finite-length microchannels for prescribed wall heat flux boundary conditions, including the effects of rarefaction, streamwise conduction, and viscous dissipation. The analytical solution proposed, valid for low-intermediate Peclet values...

Full description

Bibliographic Details
Main Authors: Antonio Brasiello, Alessandra Adrover
Format: Article
Language:English
Published: Hindawi Limited 2020-01-01
Series:International Journal of Chemical Engineering
Online Access:http://dx.doi.org/10.1155/2020/8884393
id doaj-e382ad71b92649ebbd99a7dbe67d1189
record_format Article
spelling doaj-e382ad71b92649ebbd99a7dbe67d11892021-07-02T10:53:19ZengHindawi LimitedInternational Journal of Chemical Engineering1687-806X1687-80782020-01-01202010.1155/2020/88843938884393Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat FluxAntonio Brasiello0Alessandra Adrover1Dipartimento di Ingegneria Chimica, Materiali e Ambiente, Sapienza Università degli Studi di Roma, Via Eudossiana 18, Roma 00184, ItalyDipartimento di Ingegneria Chimica, Materiali e Ambiente, Sapienza Università degli Studi di Roma, Via Eudossiana 18, Roma 00184, ItalyThe article addresses the extended Graetz–Nusselt problem in finite-length microchannels for prescribed wall heat flux boundary conditions, including the effects of rarefaction, streamwise conduction, and viscous dissipation. The analytical solution proposed, valid for low-intermediate Peclet values, takes into account the presence of the thermal development region. The influence of all transport parameters (Peclet Pe, Knudsen Kn, and Brinkman Br) and geometrical parameters (entry length and microchannel aspect ratio) is investigated. Performances of different wall heat flux functions have been analyzed in terms of the averaged Nusselt number. In the absence of viscous dissipation Br=0, the best heating protocol is a decreasing wall heat flux function. In the presence of dissipation Br>0, the best heating protocol is a uniform wall heat flux.http://dx.doi.org/10.1155/2020/8884393
collection DOAJ
language English
format Article
sources DOAJ
author Antonio Brasiello
Alessandra Adrover
spellingShingle Antonio Brasiello
Alessandra Adrover
Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
International Journal of Chemical Engineering
author_facet Antonio Brasiello
Alessandra Adrover
author_sort Antonio Brasiello
title Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
title_short Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
title_full Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
title_fullStr Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
title_full_unstemmed Significance of Rarefaction, Streamwise Conduction, and Viscous Dissipation on the Extended Graetz–Nusselt Problem: The Case of Finite-Length Microchannels with Prescribed Wall Heat Flux
title_sort significance of rarefaction, streamwise conduction, and viscous dissipation on the extended graetz–nusselt problem: the case of finite-length microchannels with prescribed wall heat flux
publisher Hindawi Limited
series International Journal of Chemical Engineering
issn 1687-806X
1687-8078
publishDate 2020-01-01
description The article addresses the extended Graetz–Nusselt problem in finite-length microchannels for prescribed wall heat flux boundary conditions, including the effects of rarefaction, streamwise conduction, and viscous dissipation. The analytical solution proposed, valid for low-intermediate Peclet values, takes into account the presence of the thermal development region. The influence of all transport parameters (Peclet Pe, Knudsen Kn, and Brinkman Br) and geometrical parameters (entry length and microchannel aspect ratio) is investigated. Performances of different wall heat flux functions have been analyzed in terms of the averaged Nusselt number. In the absence of viscous dissipation Br=0, the best heating protocol is a decreasing wall heat flux function. In the presence of dissipation Br>0, the best heating protocol is a uniform wall heat flux.
url http://dx.doi.org/10.1155/2020/8884393
work_keys_str_mv AT antoniobrasiello significanceofrarefactionstreamwiseconductionandviscousdissipationontheextendedgraetznusseltproblemthecaseoffinitelengthmicrochannelswithprescribedwallheatflux
AT alessandraadrover significanceofrarefactionstreamwiseconductionandviscousdissipationontheextendedgraetznusseltproblemthecaseoffinitelengthmicrochannelswithprescribedwallheatflux
_version_ 1721331729226006528

Similar Items