Invitation and Sponsorship:
Promod Vohra, Dean
College
of Engineering and Engineering Technology
Northern Illinois University (NIU)
Organization by M. Kostic, Professor of Mechanical Engineering, NIU
Northern Illinois University: www.niu.edu
College of Engineering and Engineering Technology: www.ceet.niu.edu
Department of Mechanical Engineering:
http://www.niu.edu/me/
Organized/Posted by Prof. M. Kostic: www.kostic.niu.edu (see
elsewhere for other Seminars/Presentations)
Driving Directions to NIU
Engineering Building *NIU-EB-map*
[Also
MK
NIU Map]
Selected Prior Presentations:
A. Mansoori '10*
S. Choi (ANLL)'06&'04
* K.F. Ehmann (NWU)
|
|
Invitation and Sponsorship:
Promod Vohra, Dean Northern Illinois University (NIU)
Organization by M. Kostic, Professor of Mechanical Engineering, NIU |
Seminar Lecture at Northern
Illinois University
NIU Engineering Building - EB Event Room
354
at Noon on Friday 9 March 2012
Refreshment at 11:30 AM * No registration required *
[PDF
Seminar Flier]
UPDATED Info at:
www.kostic.niu.edu/Seminars/Zhang2012NIU.htm
MICRO/NANOSCALE HEAT
TRANSFER:
Interfacial
Effects Dominate the Heat Transfer
Xing Zhang, Director and Professor
Institute of Engineering Thermophysics
Department of Engineering Mechanics
Tsinghua University, Beijing, China (Wiki)
Chair, Executive Committee for the Beijing2018_IHTC-16
President, Chinese Heat and mass Transfer Society (Also 与会学者合影[前排左起)
ABSTRACT:
The effects of size on heat conduction in nanofilms, convective heat transfer in micro/nanochannels, and near-field radiation in nanogaps are described. As the size is reduced, the ratio of the surface area to the volume increases; therefore, the relative importance of the interfacial effects also increases. The physical mechanisms for these size effects have been classified into two categories. When the scale is reduced to the order of micrometers (except for gases), the interfaces only affect the macro parameters and the continuum assumption still holds, but the relative importance of the various forces (inertia force, viscous force, buoyancy, etc.) and effects (interfacial effect, axial heat conduction in the tube wall, etc.) changes, resulting in changes in the heat transfer characteristics from normal conditions. As the size is further reduced to the order of submicrometers or nanometers, the interface affects not only the macro parameters but also the micro parameters (mean free path, relaxation time, etc.) so the continuum assumption breaks down and Newton’s viscosity law and Fourier’s heat conduction law are no longer applicable. Thus, the major characteristic of micro/nanoscale heat transfer is that the interfacial effects dominate the heat transfer.
[PDF
Seminar Flier]
Address
questions if any to: Professor M.
Kostic:
kostic@niu.edu
<
www.kostic.niu.edu > Also
DRnanofluids
NIU Calendar:
UPDATED Info at:
www.kostic.niu.edu/Seminars/Zhang2012NIU.htm