Documents disponibles écrits par cet auteur

Mathematical analysis of fluid flow and mass transfer in a cross flow tubular membrane / M. Kostoglou in Industrial & engineering chemistry research, Vol. 48 N° 12 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5885–5893 Titre : Mathematical analysis of fluid flow and mass transfer in a cross flow tubular membrane Type de document : texte imprimé Auteurs : M. Kostoglou, Auteur ; A. J. Karabelas, Auteur Année de publication : 2009 Article en page(s) : pp. 5885–5893 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Cross-flow  tubular  membranes  Mathematical  analysis  Integral  equations Résumé : A mathematical analysis is presented for a simplified model of cross-flow in tubular membranes, for which a numerical treatment was recently reported. It is shown, step by step, that by using several asymptotic and analytical techniques the number of dimensionless numbers governing the problem can be reduced. Results are derived in terms of algebraic or integral equations, with accuracy comparable to those obtained from the complicated numerical solution. The analysis performed here permits an improved insight into the structure of the problem, compared to the numerical technique, and facilitates explanation of the numerically obtained results. The present approach can, in principle, be generalized for application to more complicated models of the particular process. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900056c [article] Mathematical analysis of fluid flow and mass transfer in a cross flow tubular membrane [texte imprimé] / M. Kostoglou, Auteur ; A. J. Karabelas, Auteur . - 2009 . - pp. 5885–5893. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5885–5893 Mots-clés : Cross-flow  tubular  membranes  Mathematical  analysis  Integral  equations Résumé : A mathematical analysis is presented for a simplified model of cross-flow in tubular membranes, for which a numerical treatment was recently reported. It is shown, step by step, that by using several asymptotic and analytical techniques the number of dimensionless numbers governing the problem can be reduced. Results are derived in terms of algebraic or integral equations, with accuracy comparable to those obtained from the complicated numerical solution. The analysis performed here permits an improved insight into the structure of the problem, compared to the numerical technique, and facilitates explanation of the numerically obtained results. The present approach can, in principle, be generalized for application to more complicated models of the particular process. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900056c

On the effect of flowing circular entities swarms on strip electrodes conductance / M. Kostoglou in Industrial & engineering chemistry research, Vol. 51 N° 15 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 15 (Avril 2012) . - pp. 5615-5625 Titre : On the effect of flowing circular entities swarms on strip electrodes conductance Type de document : texte imprimé Auteurs : M. Kostoglou, Auteur Année de publication : 2012 Article en page(s) : pp. 5615-5625 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrodes Résumé : The use of finite size conductance electrode strips for the identification of dispersed phase flows may lead to difficulties related to the failure of homogeneous theories for the effective conductivity of dispersions in the particular geometry. In this context, a model problem is presented here: circular nonconducting entities dispersed in a conducting liquid flow at constant velocity over a nonconducting wall with strip electrodes flush mounted on it. The mathematical model is formulated in detail and is decomposed to electrostatic and to swarm generation subproblems. The electrostatic problem is simplified for dilute swarm of small, compared to the electrode width, entities for which an approximate analytical closed form solution is derived. A stochastic algorithm is developed for the generation of entity swarms. It is shown that a swarm generates fluctuations to the effective conductance measured by the electrodes. The strength of the fluctuations is related to the variations of the local electric current magnitude of the electrical field undisturbed by the entities at a distance equal to the average distance between entities. The present work is a first step to understand the interaction between entity swarms flowing over strip electrodes in order to explore the possibility of exploiting the fluctuating conductance signal for the characterization of the swarm further to a simple volume fraction determination. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25815842 [article] On the effect of flowing circular entities swarms on strip electrodes conductance [texte imprimé] / M. Kostoglou, Auteur . - 2012 . - pp. 5615-5625. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 15 (Avril 2012) . - pp. 5615-5625 Mots-clés : Electrodes Résumé : The use of finite size conductance electrode strips for the identification of dispersed phase flows may lead to difficulties related to the failure of homogeneous theories for the effective conductivity of dispersions in the particular geometry. In this context, a model problem is presented here: circular nonconducting entities dispersed in a conducting liquid flow at constant velocity over a nonconducting wall with strip electrodes flush mounted on it. The mathematical model is formulated in detail and is decomposed to electrostatic and to swarm generation subproblems. The electrostatic problem is simplified for dilute swarm of small, compared to the electrode width, entities for which an approximate analytical closed form solution is derived. A stochastic algorithm is developed for the generation of entity swarms. It is shown that a swarm generates fluctuations to the effective conductance measured by the electrodes. The strength of the fluctuations is related to the variations of the local electric current magnitude of the electrical field undisturbed by the entities at a distance equal to the average distance between entities. The present work is a first step to understand the interaction between entity swarms flowing over strip electrodes in order to explore the possibility of exploiting the fluctuating conductance signal for the characterization of the swarm further to a simple volume fraction determination. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25815842

On the fluid mechanics of spiral-wound membrane modules / M. Kostoglou in Industrial & engineering chemistry research, Vol. 48 N° 22 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10025–10036 Titre : On the fluid mechanics of spiral-wound membrane modules Type de document : texte imprimé Auteurs : M. Kostoglou, Auteur ; Anastasios J. Karabelas, Auteur Année de publication : 2010 Article en page(s) : pp. 10025–10036 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Spiral-wound  membrane  modules  Fluid  mechanics Résumé : Spiral-wound membrane (SWM) modules are comprised of several large-size membrane sheets with a net-type spacer at the retentate flow channel and a porous cloth/filler at the low-pressure permeate side; thus, two strongly interacting flow fields exist with spatially variable properties. Mathematical models of the SWM operation, based on an accurate description of transport phenomena taking place in those narrow flow passages, are necessary tools for optimizing both module design parameters and the entire membrane-based plant. Such integrated SWM models are not available at present. In this problem, the coexistence of several flow length scales, from the pores of the permeate side filler to the macroscopic dimensions of the module, renders the modeling task quite complicated. Typical modeling efforts vary between the extremes of detailed description of transport phenomena at small scale to macroscopic phenomenological-type simulation of the entire separation process in a module. The scope of this work is to describe the hydrodynamics of spiral-wound membranes, starting from first principles, to suggest and analyze some realistic approximations and their origin and to present an integrated model where linking phenomena at different length scales is an essential feature. This effort has resulted in an efficient numerical algorithm, allowing predictions of the spatial distribution of pressure, permeation, and cross-flow velocities throughout the membrane leaves. In this work, all possible analytical solutions have been derived which facilitate the development of the simulation algorithm. Typical examples of predicted flow and pressure distributions are presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901129j [article] On the fluid mechanics of spiral-wound membrane modules [texte imprimé] / M. Kostoglou, Auteur ; Anastasios J. Karabelas, Auteur . - 2010 . - pp. 10025–10036. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10025–10036 Mots-clés : Spiral-wound  membrane  modules  Fluid  mechanics Résumé : Spiral-wound membrane (SWM) modules are comprised of several large-size membrane sheets with a net-type spacer at the retentate flow channel and a porous cloth/filler at the low-pressure permeate side; thus, two strongly interacting flow fields exist with spatially variable properties. Mathematical models of the SWM operation, based on an accurate description of transport phenomena taking place in those narrow flow passages, are necessary tools for optimizing both module design parameters and the entire membrane-based plant. Such integrated SWM models are not available at present. In this problem, the coexistence of several flow length scales, from the pores of the permeate side filler to the macroscopic dimensions of the module, renders the modeling task quite complicated. Typical modeling efforts vary between the extremes of detailed description of transport phenomena at small scale to macroscopic phenomenological-type simulation of the entire separation process in a module. The scope of this work is to describe the hydrodynamics of spiral-wound membranes, starting from first principles, to suggest and analyze some realistic approximations and their origin and to present an integrated model where linking phenomena at different length scales is an essential feature. This effort has resulted in an efficient numerical algorithm, allowing predictions of the spatial distribution of pressure, permeation, and cross-flow velocities throughout the membrane leaves. In this work, all possible analytical solutions have been derived which facilitate the development of the simulation algorithm. Typical examples of predicted flow and pressure distributions are presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901129j