The Effect of Thermal Accommodation on Unsteady Microscale Heat Transfer
نویسندگان
چکیده
Thermal accommodation coefficient, one of the fundamental parameters in rarefied gas dynamics, is usually introduced to account for the fraction of incident molecules interacting with solid surface in a diffusive manner. In the present study, the effects of thermal accommodation on the unsteady one-dimensional micro-flow are examined, when the oscillating flow input is applied, by employing the unsteady DSMC technique. Since the temperature jump relation has been usually accepted as the thermal boundary condition in the analysis of MEMS flow, it is also focused on in this study. To this end, the wall heat fluxes are also obtained indirectly by applying the temperature jump relation to DSMC temperature profiles. A variation in the thermal accommodation coefficient is observed to severely affect the wall properties such as heat flux and wall pressure. In addition, the difference between indirect and direct heat flux remained unchanged even if the thermal accommodation coefficient is changed.
منابع مشابه
Dufour and Soret Effects on Unsteady Heat and Mass Transfer for Powell-Eyring Fluid Flow over an Expanding Permeable Sheet
In the present analysis, the Dufour and Soret effects on unsteady heat-mass transfer of a viscous incompressible Powell-Eyring fluids flow past an expanding/shrinking permeable sheet are reported. The fluid boundary layer develops over the variable sheet with suction/injection to the non-uniform free stream velocity. Under the symmetry group of transformations, the governing equations along wit...
متن کاملUnsteady boundary layer flow of a Casson fluid past a wedge with wall slip velocity
In this paper an analysis is presented to understand the effect of non–Newtonian rheology, velocity slip at the boundary, thermal radiation, heat absorption/generation and first order chemical reaction on unsteady MHD mixed convective heat and mass transfer of Casson fluid past a wedge in the presence of a transverse magnetic field with variable electrical conductivity. The partial differential...
متن کاملCharacterization of unsteady double-diffusive mixed convection flow with soret and dufour effects in a square enclosure with top moving lid
The present study considers the numerical examination of an unsteady thermo-solutal mixed convection when the extra mass and heat diffusions, called as Soret and Dufour effects, were not neglected. The numerical simulations were performed in a lid-driven cavity, where the horizontal walls were kept in constant temperatures and concentrations. The vertical walls were well insulated. A finite vol...
متن کاملAnalytical and numerical investigation of heat and mass transfer effects on magnetohydrodynamic natural convective flow past a vertical porous plate
The aim of this investigation is to study the effect of hall current on an unsteady natural convective flow of a viscous, incompressible, electrically conducting optically thick radiating fluid past a vertical porous plate in the presence of a uniform transverse magnetic field. The Rosseland diffusion approximation is used to describe the radiative heat flux in the energy equation. Analytical a...
متن کاملNanofluid forced convection through a microtube with constant heat flux and slip boundary
Given the need to increase the efficiency of heat transfer in thermal systems, especially systems using nanofluids in microscale and nanoscale heat transfer equipment ideas to improve their performance is very good.In present study, the flow and heat transfer of Water-Cu nanofluid in micro-tube with slip regime with constant wall heat flux numerically simulated with low Reynolds numbers. Sl...
متن کامل