PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!

Znaleziono wyników: 7

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  two-temperature model
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Identification of thermophysical parameters using an artificial immune system
Dziatkiewicz Jolanta, Poteralski Arkadiusz
Computer Assisted Methods in Engineering and Science
|
2023
|
Vol. 30, no. 4
521--537
EN
In this paper, the identification of thermophysical parameters using the hyperbolic twotemperature model is made. We investigate the influence of ultra-fast laser pulses on the heating of a thin metal film using this model. Two differential equations coupled with the electron-phonon coupling factor G are used. One of these equations concerns electron temperatures and the other addresses lattice temperatures. Appropriate initial and boundary conditions are imposed for this model. The finite difference method with a staggered grid is used to solve this direct problem. Temperatures for even nodes and heat fluxes for odd nodes are calculated. The results of the direct problem and results of the experiment are compared. In the optimization process, an artificial immune system is used.
2
Content available A generalized thermoelastic medium subjected to pulsed laser heating via a two-temperature model
Abouelregal Ahmed E., Zenkour Ashraf M.
Journal of Theoretical and Applied Mechanics
|
2019
|
Vol. 57 nr 3
631--639
EN
This article investigates stress and induced temperature in an isotropic, homogeneous, thermoelastic half-space using a two-temperature generalized thermoelasticity model. The bounding plane surface of the present half-space continuum is subjected to a non-Gaussian laser pulse. Laplace’s transform space is considered to deduce a closed-form solution to the problem. In addition, the inversions of Laplace’s transformations have been carried numerically to obtain field quantities in the transient state. The effects of parameters of two-temperature, laser-pulse and laser intensity are investigated. A concluding remark for the graphical forms of the derived expressions is presented.
3
Content available remote Second-order two-temperature model of heat transfer processes in a thin metal film subjected to an ultrashort laser pulse
Majchrzak E., Dziatkiewicz J.
Archives of Mechanics
|
2019
|
Vol. 71, nr 4-5
377--391
EN
Thermal processes in domain of thin metal film subjected to an ultrashort laser pulse are considered. A mathematical description of the process discussed is based on the system of four equations. Two of them describe the electrons and lattice temperature, while third and fourth equations represent the generalized Fourier law, it means the dependencies between the electrons (lattice) heat flux and the electrons (lattice) temperature gradient. In the generalized Fourier law the heat fluxes are delayed in relation to the temperature gradients which consequently causes the appearance of heat fluxes time derivatives in the appropriate equations. Depending on the order of the generalized Fourier law expansion into the Taylor series, the first- and the second-order model can be obtained. In contrast to the commonly used first-order model, here the second-order two-temperature model is proposed. The problem is solved using the implicit scheme of the finite difference method. The examples of computations are also presented. It turns out that for the low laser intensities the results obtained using the first- and the second-order models are very similar.
4
Content available Analysis of ultrashort laser pulse interactions with metal films using a two-temperature model
Majchrzak E., Dziatkiewicz J.
Journal of Applied Mathematics and Computational Mechanics
|
2015
|
Vol. 14, nr 2
31--39
EN
In the paper the problem of thin metal film subjected to the action of the high laser fluence and the ultrashort pulse width is considered. The mathematical model consists of the equations describing the electrons and phonons temperatures and the relationships between the heat fluxes and temperature gradients of electrons and phonons. The problem is solved using the explicit scheme of the finite difference method with staggered grid. In the final part the results of computations and conclusions are presented.
5
Content available remote Application of sensitivity analysis in microscale heat transfer
Majchrzak E., Dziatkiewicz J., Kałuża G.
Computer Assisted Methods in Engineering and Science
|
2013
|
Vol. 20, no. 2
113--121
EN
In the paper, the thin metal film subjected to the ultrashort laser pulse has been analyzed. The heat conduction in the domain considered has been described by two-temperature model consisting of the system of two coupled parabolic equations determining the electron and lattice temperatures. The sensitivity analysis of electron and lattice temperatures with respect to the parameters appearing in mathematical description has been discussed. In particular, the changes of temperatures due to the changes of coupling factor G and the film thickness L have been estimated. At the stage of numerical computations in a case of basic as well as sensitivity problems solutions the explicit scheme of finite difference method has been used. In the final part of the paper the results of computations have been shown.
6
Analiza wrażliwości cienkiej warstwy metalowej poddanej działaniu lasera
Majchrzak E., Dziatkiewicz J., Kałuża G.
Modelowanie Inżynierskie
|
2012
|
T. 12, nr 43
155-160
PL
Rozpatrywano cienką warstwę metalową poddaną działaniu lasera o ultrakrótkim impulsie. Przewodzenie ciepła w warstwie opisano za pomocą modelu dwutemperaturowego składającego się z układu dwóch sprzężonych równań parabolicznych określających temperaturę gazu elektronowego i sieci krystalicznej. Przeprowadzono analizę wrażliwości pól temperatury ze względu na grubość warstwy. W tym celu wykorzystano podejście bezpośrednie analizy wrażliwości kształtu z zastosowaniem pochodnej materialnej. Pokazano wyniki obliczeń oraz sformułowano wnioski.
EN
The thin metal film subjected to the ultrashort laser pulse has been considered. The heat conduction in thin film has been described by two-temperature model consisting of the system of two coupled parabolic eąuations determining the electron and lattice temperatures. The sensitivity analysis of temperature fields with respect to the film thickness has been done. To this end the direct approach of shape sensitivity analysis using the concept of material derivative has been applied. The results of computations have been shown and the conclusions have been formulated.
7
Content available remote Two - temperature model of microscale heat transfer
Majchrzak E., Poteralska J.
Computer Methods in Materials Science
|
2011
|
Vol. 11, No. 2
330-336
EN
Thin metal film subjected to a short-pulse laser heating is considered. The hyperbolic two-temperature model describing the temporal and spatial evolution of the lattice and electrons temperatures is discussed. At a stage of numerical computations the finite difference method is used under the assumption that a part of thermophysical parameters in mathematical model of the process considered is temperature-dependent. In the final part of the paper the examples of computations are shown.
PL
Rozpatrywano cienką warstwę metalową poddaną działaniu lasera. Procesy cieplne w analizowanym obszarze opisano dwu-temperaturowym hiperbolicznym modelem, który uwzględnia zmiany temperatury elektronów i sieci krystalicznej. Zadaniel rozwiązano za pomocą metody różnic skończonych, przy czym uwzględniono zmienne z temperaturą wartości niektórych parametrów termofizycznych. W końcowej części artykułu przedstawiono wyniki obliczeń.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.