Documents disponibles écrits par cet auteur

Inverse heat conduction in a composite slab with pyrolysis effect and temperature-dependent thermophysical properties / Jianhua Zhou in Journal of heat transfer, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 3 (Mars 2010) . - pp. [034502-1/3] Titre : Inverse heat conduction in a composite slab with pyrolysis effect and temperature-dependent thermophysical properties Type de document : texte imprimé Auteurs : Jianhua Zhou, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur Article en page(s) : pp. [034502-1/3] Note générale : Physique Langues : Anglais (eng) Mots-clés : Composite  Inverse  heat  conduction  Pyrolysis  Temperature-dependent  thermal  properties Index. décimale : 536 Chaleur. Thermodynamique Résumé : The inverse heat conduction problem (IHCP) in a one-dimensional composite slab with rate-dependent pyrolysis chemical reaction and outgassing flow effects is investigated using the iterative regularization approach. The thermal properties of the composites are considered to be temperature-dependent. A nonlinear conjugate gradient method formulation is developed and applied to solve the IHCP in an organic composite slab whose front-surface is subjected to high intensity periodic laser heating. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Inverse heat conduction in a composite slab with pyrolysis effect and temperature-dependent thermophysical properties [texte imprimé] / Jianhua Zhou, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur . - pp. [034502-1/3]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 3 (Mars 2010) . - pp. [034502-1/3] Mots-clés : Composite  Inverse  heat  conduction  Pyrolysis  Temperature-dependent  thermal  properties Index. décimale : 536 Chaleur. Thermodynamique Résumé : The inverse heat conduction problem (IHCP) in a one-dimensional composite slab with rate-dependent pyrolysis chemical reaction and outgassing flow effects is investigated using the iterative regularization approach. The thermal properties of the composites are considered to be temperature-dependent. A nonlinear conjugate gradient method formulation is developed and applied to solve the IHCP in an organic composite slab whose front-surface is subjected to high intensity periodic laser heating. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

Modeling of ultrafast phase change processes in a thin metal film irradiated by femtosecond laser pulse trains / Jing Huang in Journal of heat transfer, Vol. 133 N° 3 (Mars 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 3 (Mars 2011) . - pp. [031003/1-8] Titre : Modeling of ultrafast phase change processes in a thin metal film irradiated by femtosecond laser pulse trains Type de document : texte imprimé Auteurs : Jing Huang, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur Année de publication : 2011 Article en page(s) : pp. [031003/1-8] Note générale : Physique Langues : Anglais (eng) Mots-clés : Gold  Laser  beam  effects  Melting  Metallic  thin  films  Phase  change  materials  Solidification  Vaporisation Index. décimale : 536 Chaleur. Thermodynamique Résumé : Ultrashort laser pulses can be generated in the form of a pulse train. In this paper, the ultrafast phase change processes of a 1 µm free-standing gold film irradiated by femtosecond laser pulse trains are simulated numerically. A two-temperature model coupled with interface tracking method is developed to describe the ultrafast melting, vaporization, and resolidification processes. To deal with the large span in time scale, variable time steps are adopted. A laser pulse train consists of several pulse bursts with a repetition rate of 0.5–1 MHz. Each pulse burst contains 3–10 pulses with an interval of 50 ps–10 ns. The simulation results show that with such configuration, to achieve the same melting depth, the maximum temperature in the film decreases significantly in comparison to that of a single pulse. Although the total energy depositing on the film will be lifted, more energy will be transferred into the deeper part, instead of accumulating in the subsurface layer. This leads to lower temperature and temperature gradient, which is favorable in laser sintering and laser machining. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] Modeling of ultrafast phase change processes in a thin metal film irradiated by femtosecond laser pulse trains [texte imprimé] / Jing Huang, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur . - 2011 . - pp. [031003/1-8]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 3 (Mars 2011) . - pp. [031003/1-8] Mots-clés : Gold  Laser  beam  effects  Melting  Metallic  thin  films  Phase  change  materials  Solidification  Vaporisation Index. décimale : 536 Chaleur. Thermodynamique Résumé : Ultrashort laser pulses can be generated in the form of a pulse train. In this paper, the ultrafast phase change processes of a 1 µm free-standing gold film irradiated by femtosecond laser pulse trains are simulated numerically. A two-temperature model coupled with interface tracking method is developed to describe the ultrafast melting, vaporization, and resolidification processes. To deal with the large span in time scale, variable time steps are adopted. A laser pulse train consists of several pulse bursts with a repetition rate of 0.5–1 MHz. Each pulse burst contains 3–10 pulses with an interval of 50 ps–10 ns. The simulation results show that with such configuration, to achieve the same melting depth, the maximum temperature in the film decreases significantly in comparison to that of a single pulse. Although the total energy depositing on the film will be lifted, more energy will be transferred into the deeper part, instead of accumulating in the subsurface layer. This leads to lower temperature and temperature gradient, which is favorable in laser sintering and laser machining. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]

Size effects during femtosecond laser interaction with nanosized metal particles / Jing Huang in Journal of heat transfer, Vol. 134 N° 1 (Janvier 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol. 134 N° 1 (Janvier 2012) . - 07 p. Titre : Size effects during femtosecond laser interaction with nanosized metal particles Type de document : texte imprimé Auteurs : Jing Huang, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Heat teansfer Langues : Anglais (eng) Mots-clés : Evaporation  Gold  High-speed  optical  techniques  Laser  beam  effects  Laser  sintering  Melting  Nanoparticles  Particle  size  Solidification Index. décimale : 536 Chaleur. Thermodynamique Résumé : To obtain more in-depth knowledge about the microscopic process during laser sintering, phase change processes including melting, evaporation, and resolidification during the irradiation of femtosecond laser on nanosized gold particles were simulated. The effects of multiple reflections and pulse energy overlapping in small particle size were considered. The results show that when the particle size is big enough, the simulation results match those of old model. When the particle size is small and laser fluence is high, no resolidification takes place in the time range of the simulation. The laser fluence range to achieve partial melting is narrow when the particle is small. When the diameter is smaller than 400 nm, temperature gradient during the heating period is ignorable, which is different from the large particles. The threshold value of laser fluence to achieve vaporization is about two times higher than that of melting with the same particle size. DEWEY : 536 ISSN : 0022-1481 En ligne : http://www.asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013400 [...] [article] Size effects during femtosecond laser interaction with nanosized metal particles [texte imprimé] / Jing Huang, Auteur ; Yuwen Zhang, Auteur ; J. K. Chen, Auteur . - 2012 . - 07 p. Heat teansfer Langues : Anglais (eng) in Journal of heat transfer > Vol. 134 N° 1 (Janvier 2012) . - 07 p. Mots-clés : Evaporation  Gold  High-speed  optical  techniques  Laser  beam  effects  Laser  sintering  Melting  Nanoparticles  Particle  size  Solidification Index. décimale : 536 Chaleur. Thermodynamique Résumé : To obtain more in-depth knowledge about the microscopic process during laser sintering, phase change processes including melting, evaporation, and resolidification during the irradiation of femtosecond laser on nanosized gold particles were simulated. The effects of multiple reflections and pulse energy overlapping in small particle size were considered. The results show that when the particle size is big enough, the simulation results match those of old model. When the particle size is small and laser fluence is high, no resolidification takes place in the time range of the simulation. The laser fluence range to achieve partial melting is narrow when the particle is small. When the diameter is smaller than 400 nm, temperature gradient during the heating period is ignorable, which is different from the large particles. The threshold value of laser fluence to achieve vaporization is about two times higher than that of melting with the same particle size. DEWEY : 536 ISSN : 0022-1481 En ligne : http://www.asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013400 [...]