The present investigation is devoted to the fully developed slip flow mixed convection in vertical microducts of two different cross sections, namely, polygon, with circle as a limiting case, and rectangle. The two axially constant heat flux boundary conditions of H1 and H2 are considered in the analysis. The velocity and temperature discontinuities at the boundary are incorporated into the solutions using the first-order slip boundary conditions. The method considered is mainly analytical in which the governing equations in cylindrical coordinates along with the symmetry conditions and finiteness of the flow parameter at the origin are exactly satisfied. The first-order slip boundary conditions are then applied to the solution using the point matching technique. The results show that both the Nusselt number and the pressure drop parameter are increasing functions of the Grashof to Reynolds ratio. It is also found that, with the exception of the H2 Nusselt number of the triangular duct, which shows an opposite trend, both the Nusselt number and the pressure drop are decreased by increasing the Knudsen number. Furthermore, the pressure drop of the H2 case is found to be higher than that obtained by assuming an H1 thermal boundary condition.

Article navigation

March 2014

Research-Article

# Gaseous Slip Flow Mixed Convection in Vertical Microducts With Constant Axial Energy Input

Arman Sadeghi,

Sharif University of Technology,

Tehran,

e-mail: armansadeghi@mech.sharif.edu

Arman Sadeghi

School of Mechanical Engineering

,Sharif University of Technology,

P.O. Box 11155-9567

,Tehran,

Iran

e-mail: armansadeghi@mech.sharif.edu

Search for other works by this author on:

Mostafa Baghani,

College of Engineering,

University of Tehran,

Tehran,

e-mail: baghani@ut.ac.ir

Mostafa Baghani

School of Mechanical Engineering

,College of Engineering,

University of Tehran,

P.O. Box 11155-4563

,Tehran,

Iran

e-mail: baghani@ut.ac.ir

Search for other works by this author on:

Mohammad Hassan Saidi

Sharif University of Technology,

Tehran,

e-mail: saman@sharif.edu

Mohammad Hassan Saidi
1

School of Mechanical Engineering

,Sharif University of Technology,

P.O. Box 11155-9567

,Tehran,

Iran

e-mail: saman@sharif.edu

1Corresponding author.

Search for other works by this author on:

Arman Sadeghi

School of Mechanical Engineering

,Sharif University of Technology,

P.O. Box 11155-9567

,Tehran,

Iran

e-mail: armansadeghi@mech.sharif.edu

Mostafa Baghani

School of Mechanical Engineering

,College of Engineering,

University of Tehran,

P.O. Box 11155-4563

,Tehran,

Iran

e-mail: baghani@ut.ac.ir

Mohammad Hassan Saidi

School of Mechanical Engineering

,Sharif University of Technology,

P.O. Box 11155-9567

,Tehran,

Iran

e-mail: saman@sharif.edu

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received September 9, 2012; final manuscript received October 27, 2013; published online December 23, 2013. Assoc. Editor: Oronzio Manca.

*J. Heat Transfer*. Mar 2014, 136(3): 032501 (13 pages)

**Published Online:**December 23, 2013

Article history

Received:

September 9, 2012

Revision Received:

October 27, 2013

Citation

Sadeghi, A., Baghani, M., and Saidi, M. H. (December 23, 2013). "Gaseous Slip Flow Mixed Convection in Vertical Microducts With Constant Axial Energy Input." ASME. *J. Heat Transfer*. March 2014; 136(3): 032501. https://doi.org/10.1115/1.4025919

Download citation file:

- Ris (Zotero)
- Reference Manager
- EasyBib
- Bookends
- Mendeley
- Papers
- EndNote
- RefWorks
- BibTex
- ProCite
- Medlars

Close

#### Sign In

### Get Email Alerts

### Cited By

A Correlation for Nusselt Number of Slip Gas Flow in Confined Porous Media

J. Heat Transfer (September 2020)

The Validity of Approximate Boundary Conditions for Natural Convection With Thermal Radiation in Open Cavities

J. Heat Transfer (September 2020)

### Related Articles

Mixed Convection in a Vertical Microannulus Between Two Concentric Microtubes

J. Heat Transfer (January,2009)

Asymmetrical Heating in Rarefied Flows Through Circular Microchannels

J. Heat Transfer (September,2014)

Slip Flow Heat Transfer in Annular Microchannels With Constant Heat Flux

J. Heat Transfer (September,2008)

Gas Microflows in the Slip Flow Regime: A Critical Review on Convective Heat Transfer

J. Heat Transfer (February,2012)

### Related Proceedings Papers

### Related Chapters

Mixed-Up Convection

Hot Air Rises and Heat Sinks: Everything You Know about Cooling Electronics Is Wrong

Natural and Mixed Convection

Thermal Management of Microelectronic Equipment

Natural and Mixed Convection

Thermal Management of Microelectronic Equipment, Second Edition