We investigate the constant-wall-temperature convective heat-transfer characteristics of a model gaseous flow in two-dimensional micro and nano-channels under hydrodynamically and thermally fully developed conditions. Our investigation covers both the slip-flow regime 0<Kn<0.1, and most of the transition regime 0.1,Kn<10, where Kn, the Knudsen number, is defined as the ratio between the molecul...

Molecular Dynamics Simulations of Heat Transfer in Nanoscale Liquid Films. (May 2009) Bo Hung Kim, B.A., Yonsei University; M.S., Texas A&M University Co-Chairs of Advisory Committee: Dr. Ali Beskok Dr. Tahir Cagin Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot pro...

cp = specific heat at constant pressure, J= kg K cv = specific heat at constant volume, J= kg K E = total energy, J=m Ev = vibrational energy, J=m h = specific enthalpy, J=kg h = heat of formation, J=kg Keq = Equilibrium constant kB = Boltzmann’s constant, 1:381 10 23 J=K kb = backward reaction coefficient kf = forward reaction coefficient M = molecular weight, kg=mole NA = Avogadro’s number, 6...

in this paper, two-dimensional heat transfer in a semi-infinite wall with fins of rectangular profile has been investigated. the conduction equations of the wall and fins are solved simultaneously by a numerical method. the principal parameters of the problem are the fin spacing, length, and fin-to-wall conductivity ratio. in this investigation, the effect of these parameters on two-dimensional...

We investigate the speed of approach to Maxwellian equilibrium for a collisionless gas enclosed in a vessel whose wall are kept at a uniform, constant temperature, assuming diffuse reflection of gas molecules on the vessel wall. We establish lower bounds for potential decay rates assuming uniform Lp bounds on the initial distribution function. We also obtain a decay estimate in the spherically ...

Natural convection heat transfer has many applications in different fields of industry; such as cooling industries, electronic transformer devices and ventilation equipment; due to simple process, economic advantage, low noise and renewed retrieval. Recently, heat transfer of nanofluids have been considered because of higher thermal conductivity coefficient compared with those of ordinary fluid...

A numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. The continuity and momentum equations were solved first, assuming the wall Reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. The results show that at constant inlet and...

The second law performance of double diffusive forced convection in a horizontal porous channel with thick walls was considered. The Soret effect is included in the concentration equation and the first order chemical reaction was chosen for the concentration boundary conditions at the porous-solid walls interfaces. This investigation is focused on two principal types of boundary conditions. The...

In the present paper, natural convection fluid flow and heat transfer in a square cavity heated from below and cooled from sides and the ceiling with a thin fin attached to its hot bottom wall is investigated numerically. The right and the left walls of the cavity, as well as its horizontal top wall are maintained at a constant temperature Tc, while the bottom wall is kept at a constant tempera...

Free-convection flow through a two-dimensional rectangular box having openings at opposite corners on the vertical walls is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. Convection is induced when the box's ceiling or its floor is imposed with a temperature that is different to that of the ambient fluid, while all other walls are insulated. Th...