Documents disponibles écrits par cet auteur

Natural convection in a saturated variable-porosity medium due to microwave heating / Watit Pakdee in Journal of heat transfer, Vol. 133 N° 6 (Juin 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 6 (Juin 2011) . - pp. [062502/1-8] Titre : Natural convection in a saturated variable-porosity medium due to microwave heating Type de document : texte imprimé Auteurs : Watit Pakdee, Auteur ; Phadungsak Rattanadecho, Auteur Année de publication : 2011 Article en page(s) : pp. [062502/1-8] Note générale : Physique Langues : Anglais (eng) Mots-clés : Microwave  heating  Variable  porosity  Natural  convection  Saturated  porous  media  Rectangular  waveguide Index. décimale : 536 Chaleur. Thermodynamique Résumé : Microwave heating of a porous medium with a nonuniform porosity is numerically investigated based on a proposed numerical model. A two-dimensional variation of porosity of the medium is considered. The generalized non-Darcian model developed takes into account the presence of a solid drag and the inertial effect. The transient Maxwell's equations are solved by using the finite difference time domain method to describe the electromagnetic field in the waveguide and medium. The temperature profile and velocity field within a medium are determined by solution of the momentum, energy, and Maxwell's equations. The coupled nonlinear set of these equations is solved using the SIMPLE algorithm. In this work, a detailed parametric study is conducted on heat transport inside a rectangular enclosure filled with a saturated porous medium of constant or variable porosity. The numerical results agree well with the experimental data. Variations in porosity significantly affect the microwave heating process as well as the convective flow pattern driven by microwave energy. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Natural convection in a saturated variable-porosity medium due to microwave heating [texte imprimé] / Watit Pakdee, Auteur ; Phadungsak Rattanadecho, Auteur . - 2011 . - pp. [062502/1-8]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 6 (Juin 2011) . - pp. [062502/1-8] Mots-clés : Microwave  heating  Variable  porosity  Natural  convection  Saturated  porous  media  Rectangular  waveguide Index. décimale : 536 Chaleur. Thermodynamique Résumé : Microwave heating of a porous medium with a nonuniform porosity is numerically investigated based on a proposed numerical model. A two-dimensional variation of porosity of the medium is considered. The generalized non-Darcian model developed takes into account the presence of a solid drag and the inertial effect. The transient Maxwell's equations are solved by using the finite difference time domain method to describe the electromagnetic field in the waveguide and medium. The temperature profile and velocity field within a medium are determined by solution of the momentum, energy, and Maxwell's equations. The coupled nonlinear set of these equations is solved using the SIMPLE algorithm. In this work, a detailed parametric study is conducted on heat transport inside a rectangular enclosure filled with a saturated porous medium of constant or variable porosity. The numerical results agree well with the experimental data. Variations in porosity significantly affect the microwave heating process as well as the convective flow pattern driven by microwave energy. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

Numerical analysis of specific absorption rate and heat transfer in the human body exposed to leakage electromagnetic field at 915 MHz and 2450 MHz / Teerapot Wessapan in Journal of heat transfer, Vol. 133 N° 5 (Mai 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 5 (Mai 2011) . - pp. [051101/1-13] Titre : Numerical analysis of specific absorption rate and heat transfer in the human body exposed to leakage electromagnetic field at 915 MHz and 2450 MHz Type de document : texte imprimé Auteurs : Teerapot Wessapan, Auteur ; Siramate Srisawatdhisukul, Auteur ; Phadungsak Rattanadecho, Auteur Année de publication : 2011 Article en page(s) : pp. [051101/1-13] Note générale : Physique Langues : Anglais (eng) Mots-clés : Microwave  Temperature  distribution  Specific  absorption  rate  Human  body Index. décimale : 536 Chaleur. Thermodynamique Résumé : In recent years, society has increased utilization of electromagnetic radiation in various applications. This radiation interacts with the human body and may lead to detrimental effects on human health. However, the resulting thermophysiologic response of the human body is not well understood. In order to gain insight into the phenomena occurring within the human body with temperature distribution induced by electromagnetic field, a detailed knowledge of absorbed power distribution is necessary. In this study, the effects of operating frequency and leakage power density on distributions of specific absorption rate and temperature profile within the human body are systematically investigated. This study focuses attention on organs in the human trunk. The specific absorption rate and the temperature distribution in various tissues, obtained by numerical solution of electromagnetic wave propagation coupled with unsteady bioheat transfer problem, are presented. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] Numerical analysis of specific absorption rate and heat transfer in the human body exposed to leakage electromagnetic field at 915 MHz and 2450 MHz [texte imprimé] / Teerapot Wessapan, Auteur ; Siramate Srisawatdhisukul, Auteur ; Phadungsak Rattanadecho, Auteur . - 2011 . - pp. [051101/1-13]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 5 (Mai 2011) . - pp. [051101/1-13] Mots-clés : Microwave  Temperature  distribution  Specific  absorption  rate  Human  body Index. décimale : 536 Chaleur. Thermodynamique Résumé : In recent years, society has increased utilization of electromagnetic radiation in various applications. This radiation interacts with the human body and may lead to detrimental effects on human health. However, the resulting thermophysiologic response of the human body is not well understood. In order to gain insight into the phenomena occurring within the human body with temperature distribution induced by electromagnetic field, a detailed knowledge of absorbed power distribution is necessary. In this study, the effects of operating frequency and leakage power density on distributions of specific absorption rate and temperature profile within the human body are systematically investigated. This study focuses attention on organs in the human trunk. The specific absorption rate and the temperature distribution in various tissues, obtained by numerical solution of electromagnetic wave propagation coupled with unsteady bioheat transfer problem, are presented. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]

Specific absorption rate and temperature increase in human eye subjected to electromagnetic fields at 900 MHz / Teerapot Wessapan in Journal of heat transfer, Vol 134 N° 9 (Septembre 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol 134 N° 9 (Septembre 2012) . - 11 p. Titre : Specific absorption rate and temperature increase in human eye subjected to electromagnetic fields at 900 MHz Type de document : texte imprimé Auteurs : Teerapot Wessapan, Auteur ; Phadungsak Rattanadecho, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : heat transfer Langues : Anglais (eng) Mots-clés : electromagnetic  fields;  temperature  distribution;  specefic  absorption  rate;  human  eye;  heat  transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : Human eye is one of the most sensitive parts of the entire human body when exposed to electromagnetic fields. These electromagnetic fields interact with the human eye and may lead to cause a variety of ocular effects from high intensity radiation. However, the resulting thermo-physiologic response of the human eye to electromagnetic fields is not well understood. In order to gain insight into the phenomena occurring within the human eye with temperature distribution induced by electromagnetic fields, a detailed knowledge of absorbed power distribution as well as temperature distribution is necessary. This study presents a numerical analysis of specific absorption rate (SAR) and heat transfer in the heterogeneous human eye model exposed to electromagnetic fields. In the heterogeneous human eye model, the effect of power density on specific absorption rate and temperature distribution within the human eye is systematically investigated. In particular, the results calculated from a developed heat transfer model, considered natural convection and porous media theory, are compared with the results obtained from a conventional heat transfer model (based on conduction heat transfer). In all cases, the temperatures obtained from the developed heat transfer model have a lower temperature gradient than that of the conventional heat transfer model. The specific absorption rate and the temperature distribution in various parts of the human eye during exposure to electromagnetic fields at 900 MHz, obtained by numerical solution of electromagnetic wave propagation and heat transfer equation, are also presented. The results show that the developed heat transfer model, which is the more accurate way to determine the temperature increase in the human eye due to electromagnetic energy absorption from electromagnetic field exposure. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000009 [...] [article] Specific absorption rate and temperature increase in human eye subjected to electromagnetic fields at 900 MHz [texte imprimé] / Teerapot Wessapan, Auteur ; Phadungsak Rattanadecho, Auteur . - 2012 . - 11 p. heat transfer Langues : Anglais (eng) in Journal of heat transfer > Vol 134 N° 9 (Septembre 2012) . - 11 p. Mots-clés : electromagnetic  fields;  temperature  distribution;  specefic  absorption  rate;  human  eye;  heat  transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : Human eye is one of the most sensitive parts of the entire human body when exposed to electromagnetic fields. These electromagnetic fields interact with the human eye and may lead to cause a variety of ocular effects from high intensity radiation. However, the resulting thermo-physiologic response of the human eye to electromagnetic fields is not well understood. In order to gain insight into the phenomena occurring within the human eye with temperature distribution induced by electromagnetic fields, a detailed knowledge of absorbed power distribution as well as temperature distribution is necessary. This study presents a numerical analysis of specific absorption rate (SAR) and heat transfer in the heterogeneous human eye model exposed to electromagnetic fields. In the heterogeneous human eye model, the effect of power density on specific absorption rate and temperature distribution within the human eye is systematically investigated. In particular, the results calculated from a developed heat transfer model, considered natural convection and porous media theory, are compared with the results obtained from a conventional heat transfer model (based on conduction heat transfer). In all cases, the temperatures obtained from the developed heat transfer model have a lower temperature gradient than that of the conventional heat transfer model. The specific absorption rate and the temperature distribution in various parts of the human eye during exposure to electromagnetic fields at 900 MHz, obtained by numerical solution of electromagnetic wave propagation and heat transfer equation, are also presented. The results show that the developed heat transfer model, which is the more accurate way to determine the temperature increase in the human eye due to electromagnetic energy absorption from electromagnetic field exposure. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000009 [...]

Theoretical Analysis of Microwave Heating of dielectric materials filled in a rectangular waveguide with various resonator distances / Phadungsak Rattanadecho 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. [031008/1-10] Titre : Theoretical Analysis of Microwave Heating of dielectric materials filled in a rectangular waveguide with various resonator distances Type de document : texte imprimé Auteurs : Phadungsak Rattanadecho, Auteur ; Waraporn Klinbun, Auteur Année de publication : 2011 Article en page(s) : pp. [031008/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Microwave  heating  Rectangular  waveguide  TE10  mode  Porous  medium  Resonator Index. décimale : 536 Chaleur. Thermodynamique Résumé : This paper proposes mathematical models of the microwave heating process of dielectric materials filled in a rectangular waveguide with a resonator. A microwave system supplies a monochromatic wave in a fundamental mode (TE10 mode). A convection exchange at the upper surface of the sample is considered. The effects of resonator distance and operating frequency on distributions of electromagnetic fields inside the waveguide, temperature profile, and flow pattern within the sample are investigated. The finite-difference time-domain method is used to determine the electromagnetic field distribution in a microwave cavity by solving the transient Maxwell equations. The finite control volume method based on the SIMPLE algorithm is used to predict the heat transfer and fluid flow model. Two dielectric materials, saturated porous medium and water, are chosen to display microwave heating phenomena. The simulation results agree well with the experimental data. Based on the results obtained, the inserted resonator has a strong effect on the uniformity of temperature distributions, depending on the penetration depth of microwave. The optimum distances of the resonator depend greatly on the operating frequencies. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] Theoretical Analysis of Microwave Heating of dielectric materials filled in a rectangular waveguide with various resonator distances [texte imprimé] / Phadungsak Rattanadecho, Auteur ; Waraporn Klinbun, Auteur . - 2011 . - pp. [031008/1-10]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 3 (Mars 2011) . - pp. [031008/1-10] Mots-clés : Microwave  heating  Rectangular  waveguide  TE10  mode  Porous  medium  Resonator Index. décimale : 536 Chaleur. Thermodynamique Résumé : This paper proposes mathematical models of the microwave heating process of dielectric materials filled in a rectangular waveguide with a resonator. A microwave system supplies a monochromatic wave in a fundamental mode (TE10 mode). A convection exchange at the upper surface of the sample is considered. The effects of resonator distance and operating frequency on distributions of electromagnetic fields inside the waveguide, temperature profile, and flow pattern within the sample are investigated. The finite-difference time-domain method is used to determine the electromagnetic field distribution in a microwave cavity by solving the transient Maxwell equations. The finite control volume method based on the SIMPLE algorithm is used to predict the heat transfer and fluid flow model. Two dielectric materials, saturated porous medium and water, are chosen to display microwave heating phenomena. The simulation results agree well with the experimental data. Based on the results obtained, the inserted resonator has a strong effect on the uniformity of temperature distributions, depending on the penetration depth of microwave. The optimum distances of the resonator depend greatly on the operating frequencies. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]