The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Stanley I. Sandler - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic modeling of confined Fluids using an extension of the generalized van der waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
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Thermodynamic modeling of confined Fluids using an extension of the generalized van der Waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
Christophe Marvillet - One of the best experts on this subject based on the ideXlab platform.
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Experimental study and modelling of heat transfer during condensation of Pure Fluid and binary mixture on a bundle of horizontal finned tubes
International Journal of Refrigeration, 2003Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Abstract An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both Pure Fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13×3 (rows × columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 °C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of Pure Fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented.
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Experimental study and modelling heat transfer during condensation of Pure Fluid and binary mixtures on a bundle of finned tubes
International Journal of Refrigeration, 2003Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both Pure Fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13×3 (rows × columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 °C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of Pure Fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented.
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Filmwise condensation of a Pure Fluid and a binary mixture in a bundle of enhanced surface tubes
International Journal of Thermal Sciences, 2002Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Abstract An experimental study has been carried out to investigate the characteristics of condensation in a bundle of horizontal tubes. These tubes have different types of external surfaces: smooth surface (1D), low trapezoidal fins with several fin pitches (2D) and specific fins (3D, C+ tube). The used Fluids are either Pure refrigerant (HFC 134a) or binary mixture of refrigerants (HFC 134a/HFC23). For the Pure Fluid and a single tube, the influence of fin spacing has been studied (11, 19, 26, 32 and 40 fins/inch) and a comparison has been made with the Gewa C+ tube. The results were analysed with the Beatty and Katz theory and compared to a specific model, taking into account both gravity and surface tension effects, developed for the Gewa C+ tube. For the bundle and for a Pure Fluid, the inundation of the lowest tubes has a strong effect on the Gewa C+ tubes performances contrary to the finned tubes. For the mixture the heat transfer coefficient decreases dramatically especially for Gewa C+ tube.
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Condensation heat transfer on enhanced surface tubes: experimental results and predictive theory
Journal of Heat Transfer, 2002Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Condensation heat transfer in a bundle of horizontal enhanced surface copper tubes (Gewa C+ tubes) has been experimentally investigated, and a comparison with trapezoidal shaped fin tubes with several fin spacing has been made. These tubes have a specific surface three-dimensional geometry (notched fins) and the Fluids used are either Pure refrigerant (HFC134a) or binary mixtures of refrigerants (HFC23/HFC134a). For the Pure Fluid and a Gewa C+ single tube, the results were analyzed with a specifically developed model, taking into account both gravity and surface tension effects. For the bundle and for a Pure Fluid, the inundation of the lowest tubes has a strong effect on the Gewa C+ tube performances contrary to the finned tubes. For the mixture, the heat transfer coefficient decreases dramatically for the Gewa C+ tube.
Marcelo Castier - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic modeling of confined Fluids using an extension of the generalized van der waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
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Thermodynamic modeling of confined Fluids using an extension of the generalized van der Waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
Leonardo Travalloni - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic modeling of confined Fluids using an extension of the generalized van der waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
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Thermodynamic modeling of confined Fluids using an extension of the generalized van der Waals theory
Chemical Engineering Science, 2010Co-Authors: Leonardo Travalloni, Marcelo Castier, Frederico W. Tavares, Stanley I. SandlerAbstract:Based on the generalized van der Waals theory, a cubic equation of state (the van der Waals equation) was extended to describe the behavior of Pure Fluids and mixtures confined in porous solids. Each pore was assumed to be a cylinder with a continuous and homogeneous surface. Fluid molecules were assumed spherical, interacting with each other and with the wall of the pore through square-well potentials. Pairwise additivity was assumed for the attractive parts of all interaction potentials. The repulsive part of the equation of state for confined Fluids was modeled based on literature data for the packing of hard spheres in cylinders. The effect of pore size on Fluid properties was explicitly represented in the model, allowing its application to both confined and bulk Fluids thus providing a consistent description of adsorption systems for all pore sizes. The resulting equation of state has two fitting parameters for each component of the Fluid, which are related to the interaction between the Fluid molecules and the pore walls. Calculations of Pure Fluid adsorption were carried out in order to analyze the sensitivity of the model to its fitting parameters and to pore size. It was found that the model is able to describe different types of adsorption isotherms. The model correlated experimental data of Pure Fluid adsorption quite well and was then used to predict the adsorption of several binary mixtures and one ternary mixture with no additional fitting, with good results. The methodological framework presented here can be extended to other widely used equations of state for modeling confined Fluids.
M. Belghazi - One of the best experts on this subject based on the ideXlab platform.
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Experimental study and modelling of heat transfer during condensation of Pure Fluid and binary mixture on a bundle of horizontal finned tubes
International Journal of Refrigeration, 2003Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Abstract An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both Pure Fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13×3 (rows × columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 °C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of Pure Fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented.
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Experimental study and modelling heat transfer during condensation of Pure Fluid and binary mixtures on a bundle of finned tubes
International Journal of Refrigeration, 2003Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both Pure Fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13×3 (rows × columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 °C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of Pure Fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented.
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Filmwise condensation of a Pure Fluid and a binary mixture in a bundle of enhanced surface tubes
International Journal of Thermal Sciences, 2002Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Abstract An experimental study has been carried out to investigate the characteristics of condensation in a bundle of horizontal tubes. These tubes have different types of external surfaces: smooth surface (1D), low trapezoidal fins with several fin pitches (2D) and specific fins (3D, C+ tube). The used Fluids are either Pure refrigerant (HFC 134a) or binary mixture of refrigerants (HFC 134a/HFC23). For the Pure Fluid and a single tube, the influence of fin spacing has been studied (11, 19, 26, 32 and 40 fins/inch) and a comparison has been made with the Gewa C+ tube. The results were analysed with the Beatty and Katz theory and compared to a specific model, taking into account both gravity and surface tension effects, developed for the Gewa C+ tube. For the bundle and for a Pure Fluid, the inundation of the lowest tubes has a strong effect on the Gewa C+ tubes performances contrary to the finned tubes. For the mixture the heat transfer coefficient decreases dramatically especially for Gewa C+ tube.
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Condensation heat transfer on enhanced surface tubes: experimental results and predictive theory
Journal of Heat Transfer, 2002Co-Authors: M. Belghazi, André Bontemps, Christophe MarvilletAbstract:Condensation heat transfer in a bundle of horizontal enhanced surface copper tubes (Gewa C+ tubes) has been experimentally investigated, and a comparison with trapezoidal shaped fin tubes with several fin spacing has been made. These tubes have a specific surface three-dimensional geometry (notched fins) and the Fluids used are either Pure refrigerant (HFC134a) or binary mixtures of refrigerants (HFC23/HFC134a). For the Pure Fluid and a Gewa C+ single tube, the results were analyzed with a specifically developed model, taking into account both gravity and surface tension effects. For the bundle and for a Pure Fluid, the inundation of the lowest tubes has a strong effect on the Gewa C+ tube performances contrary to the finned tubes. For the mixture, the heat transfer coefficient decreases dramatically for the Gewa C+ tube.
