TitleNumerical study of pressure-driven nitrogen flow in long microchannels for application to electronic cooling
NameSun, Zhanyu (author), Jaluria, Yogesh (chair), Lin, Hao (internal member), Shan, Jerry (internal member), Ozel, Tugrul (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectMechanical and Aerospace Engineering,
Electronic apparatus and appliances--Cooling
DescriptionTwo-dimensional models have been developed to investigate pressure-driven laminar nitrogen slip flow in long rectangular microchannels with characteristic lengths ranging from 1.2[mu]m to 50[mu]m and length-to-height ratios up to 2500. The large length-to-height ratio is taken to measure pressure work and viscous dissipation. Rarefaction is incorporated by modifying the boundary conditions at fluid-solid interfaces. To resolve the intense numerical effort required by the large computational domain and the quasi-steady nature of the problem, a parallel SIMPLER-based solver is developed. The influences of variable properties, rarefaction and source terms in energy equation are investigated particularly for the cases with uniform wall heat flux boundary condition and are found to be far from negligible. The thermal and hydraulic characteristics under isothermal and uniform heat flux wall boundary conditions are extensively examined and discussed for pure convection cases. It is shown that the energy taken up by pressure work is dominant over the energy generation by viscous dissipation. Rarefaction is found to influence Nusselt number in two ways: rarefaction reduces Nusselt number through the heat transfer between the wall and bulk fluid, while promotes Nusselt number by affecting the source terms in energy equation. For microchannels of larger dimensions, it is found that rarefaction effects are still significant. The conjugate heat transfer associated with microchannel slip flows is also studied. It is found that axial conduction gives a great impact on the thermal field for substrates with finite thickness. Finally, unsteady convection is studied for a larger-dimension microchannel, where the characteristic response time is found to be greatly influenced by the energy taken up by pressure work.
NoteIncludes bibliographical references (p. 155-159)
Noteby Zhanyu Sun
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.