Flow and Transport in Microchannels: Fundamental Theoretical Aspects, Experimental Methods, Application
October 3, 2005 — October 7, 2005
Coordinator:
- Peter Ehrhard (University of Dortmund , Dortmund, Germany)
Fluid flow and heat/mass transport in microchannels, i.e. in channels of considerably less than 1 mm width, have become relevant for technical applications due to the enormous progress in micro fabrication techniques. Examples for such applications are miniaturized heat exchangers, inkjet printing heads, or microchips for chemical or biological analysis (lab on a chip). Depending on the fluid, such flows may be significantly affected or even dominated by effects, which are usually neglected in macroscopic flows in comparison to the familiar effects of inertia, pressure, gravity or viscosity: Firstly, due to the large ratio of surface and volume, forces and the heat and mass transfer at interfaces play a more prominent role. Secondly, in small channels diffusive transport can become comparable to convective transport. Thirdly, in very small channels even the continuum models may be not valid. Slip, non-continuous temperatures or thermal creeping at walls
are first indications, that the continuum models and the standard boundary conditions do, at least locally, not reflect the dominant physics.
The course aims at a systematic and thorough discussion of both the theoretical and the experimental aspects within microchannel flows, complemented by an overview over some important fields of application. The focus will be on (i) the limit of continuum models towards molecular models, (ii) modifications of continuum models through e.g. adequate kinematic and thermal boundary conditions, (iii) electro-kinetic effects as electroosmosis or electrophoresis, and (iv) molecular models for microflows. The experimental techniques as (v) modifications of measuring techniques with regard to their application in microchannels and (vi) dedicated measuring techniques on extremely small scales are discussed. Further, application fields as (vii) flow and transport in microchips for chemical or biological analysis (lab on a chip) or (viii) control of flow and turbulence by micro electro-mechanical systems (MEMS) will be addressed. Finally (ix) aspects of heat transport, and thermal measurement techniques are highlighted.
Graduate students, Ph.D. students, postdoctoral researchers, and senior researchers, educated as engineers, physicists, applied mathematicians, or chemists, working or planning to work in the emerging field of microflows or related applications.