This paper presents a fractional mathematical model of a one-dimensional phase-change problem (Stefan problem) with a variable latent-heat (a power function of position). This model includes space–time fractional derivatives in the Caputo sense and time-dependent surface-heat flux. An approximate solution of this model is obtained by using the optimal homotopy asymptotic method to find the solu...

BACKGROUND Although core temperature can be measured invasively, there are currently no widely available, reliable, noninvasive thermometers for its measurement. We thus compared a prototype zero-heat-flux thermometer with simultaneous measurements from a pulmonary artery catheter. Specifically, we tested the hypothesis that zero-heat-flux temperatures are sufficiently accurate for routine clin...

This paper describes the design of a full-scale experiment to measure the heat transfer from a large pool fire to an engulfed 1.2 m diameter, 2.54 cm wall thickness hollow cylindrical calorimeter. This work is focused at determining whether temperature measurements made on the interior calorimeter surface can be used with a one-dimensional inverse conduction solver to accurately determine the h...

the large number of applications manages time varying data. existing databasetechnology seldom supports temporal database, tdb, according to time aspects.these intrinsic temporal database applications rely on such database which storesand retrieves time referenced data. moreover, applications need to be managed oncommon data items access simultaneously and to be precluded from inconsistencyas s...

Experimental studies and numerical simulation of growth and lift-off processes of single bubbles formed on designed nucleation sites have been conducted under low-gravity conditions. Merging of multiple bubbles and lift-off processes during boiling of water in the parabola flights of KC-135 aircraft were also experimentally studied. The heating area of the flat heater surface was discretized an...

In internal combustion engines, exhaust valve and its seat gain considerable temperature as the hot gases exit through them. So, the rate of heat transfer should be under control. In this study, the contact heat transfer coefficient has been estimated. An experimental study on an Air-Cooled internal combustion engine cylinder head has been considered. Using the measured temperatures of sensors ...

Abstrae--The normal-mode-expansion technique is used to obtain a semi-analytical solution for the angular distribution of radiation at any optical distance within a linearly anisotropicscattering, absorbing, emitting, non-isothermal, gray medium between two parallel reflecting boundaries. Both conservative and nonconservative cases are considered. The general problem is decomposed into simpler ...

This work uses the dual-phase-lag (DPL) model of heat conduction to demonstrate the effect of temperature gradient relaxation time on the result of non-Fourier hyperbolic conduction in a finite slab subjected to a periodic thermal disturbance. DPL model combines the wave features of hyperbolic conduction with a diffusion-like feature of the evidence not captured by the hyperbolic case. For the ...

In the present work, a modified model of heat conduction including higher order of time derivative is derived by extending Green and Naghdi theory without energy dissipation. We introduce two phase lag times to include the thermal displacement gradient and the heat flux in the heat conduction and depict microscopic responses more precisely. The constructed model is applied to s...

Transient heat conduction in semi-infinite medium with a time dependent flux as boundary condition has been solved by semi-derivative integral-balance method. Two versions fluxes have considered: power-law and exponential.