The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically "reversible", leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS = dq/T such that [symbol: see text]C ...

The effects of metal foams on heat transfer enhancement in Phase Change Materials (PCMs) are investigated. The numerical investigation is based on the two-equation non-equilibrium heat transfer model, in which the coupled heat conduction and natural convection are considered at phase transition and liquid zones. The numerical results are validated by experimental data. The main findings of the ...

the present study is concerned with optimal shape determination of inhomogeneous and temperature dependent domains under steady state heat conduction. such situations are important in many thermal design problems, especially in shape design of electronic components and chips. in the present paper, we formulate the shape optimization problem based on volume minimization of heat conductive materi...

The usual way to model heat conduction is to solve a partial differential equation (PDE) with boundary conditions (BCs), i.e., a boundary value problem (BVP). For the case of steady-state heat conduction in a homogeneous isotropic solid with thermal conductivity independent of temperature and with no heat source inside the solid, temperature T (x, y, z) in the solid verifies Laplace equation [5] :

A method is presented to determine power dissipation in piezoelectric slabs with internal losses and the resulting temperature distribution. The length of the slab is much greater than the lateral dimensions. Losses are represented using complex piezoelectric coefficients. It is shown that the spatially non-uniform power dissipation density in the slab can be determined by considering either hy...

The transient hydrodynamics and thermal behaviors of fluid flow in open-ended vertical parallel-plate porous microchannel are investigated semi-analytically under the effect of the hyperbolic heat conduction model. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the study. The Effects of Knudsen number , Darcy number , and thermal re...

Abstract Heat spreading from local, time-dependent heat sources in electronic packages results the propagation of temperature nonuniformities through stack material layers attached to chip. Available models either predict chip temperatures only steady-state or a single substrate for transient analysis, without ability response compound substrates having multiple anisotropic layers. We develop r...