Loading...
Search for:
mass-transfer-modeling
0.006 seconds
Experimental investigation in pool boiling heat transfer of pure/binary mixtures and heat transfer correlations
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 27, Issue 3 , September and October , 2008 , Pages 135-150 ; 10219986 (ISSN) ; Jamialahmadi, M ; Safekordi, A. A ; Sharif University of Technology
2008
Abstract
Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in pure component liquids with same physical properties. Several reasons should be responsible for this phenomenon, but mainly it could be related to preferential evaporation of the more volatile component(s) during bubble formation. In this article, the performances of major existing correlations to the...
A new approach to heat and mass transfer in a rotary dehumidifier: Modeling and simulation
, Article 2005 ASME Fluids Engineering Division Summer Meeting, FEDSM2005, Houston, TX, 19 June 2005 through 23 June 2005 ; Volume 2005 , 2005 , Pages 1268-1273 ; 0791837602 (ISBN); 9780791837603 (ISBN) ; Van Paassen, D ; Saidi, M. H ; ASME Fluids Engineering Division ; Sharif University of Technology
2005
Abstract
In this paper the analytical and simulation modelling of the combined heat and mass transfer processes that occur in a solid desiccant wheel is carried out. Using the numerical method, the performance of an adiabatic rotary dehumidifier is parametrically studied, and the optimal rotational speed is determined by examining the outlet adsorption-side humidity profiles. An approach to compare the solutions for different conditions used in air dehumidifier has been investigated according to the previous published studies. Comparing the simulated results with the published actual values of an experimental work substantiates the validity of model. The model accuracy with respect to the key...
Evaluation of Hollowfiber Membranes Uesd In Hemodialysis
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaei, Mohammad Jafar (Supervisor)
Abstract
Due to largre number of patients treated by dialysis and its significant increasing progress, dialysis efficiency and patients' life quality are of great interest.Dialyzer, the dialysis beating heart, has the role of cleaning blood by removing toxic solutes and balancing volume of bood's water through hollow fiber membranes. In this thesis, firstly we tried to focus on performance characteristics of dialyzer by studying effective parameters influencing dialyzer efficiency and ultimately we set two important performance characteristics, ultrafiltration coefficient and solute clearance, as our goal parameters for evaluating dialyzer's yield. To this purpose, we designed an experimental set...
The investigation of natural super-cavitation flow behind three-dimensional cavitators: Full cavitation model
, Article Applied Mathematical Modelling ; Volume 45 , 2016 , Pages 165-178 ; 0307904X (ISSN) ; Kadivar, Erfan ; Javadi, K ; Javadpour, S. M ; Sharif University of Technology
Elsevier Inc
Abstract
In this study, natural super-cavitating flow around three different conical cavitators with wedge angles of 30°, 45° and 60° is investigated. We apply the k−ϵ turbulence model and the volume of fluid (VOF) technique to numerically study the three-dimensional cavitating flow around the cavitators. The turbulence approach is coupled with a mass transfer model which is implemented into the finite-volume package. Simulations are performed for different cavitation numbers. Finally, the effects of some important parameters such as the cavitation index, inlet velocity, Froude number and wedge angle of cavitators on the geometrical characteristics of the super-cavities are discussed. Our numerical...
Separation of CO_2from N_2-CO_2Gas Mixture by Facilitated Liquid Membrane
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor)
Abstract
In this research, separation of carbon dioxide from a mixture of CO_2-N_2 with the aid of liquid membrane containing immobilized solution of diethanolamine-triethylene, known as facilitated liquid membrane, (DEA-TEG) in porous and hydrophilic poly vinylidene fluoride (PVDF) substrate was experimentally and theoretically carried out. The effects of DEA concentration, CO_2 partial pressure, and thickness of membrane on permeability coefficient, facilitation factor, permeation rate and selectivity of liquid membranewere investigated and importance of mass transfer resistance in gas phase on permeability or liquid membrane performance was also shown. Reversible reaction of complex formation...
Derivation of a Scalable Mass Ttransfer Equation for Adsorption of Uranium on Resin in Stirred Reactors
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; khanchi, Alireza (Supervisor)
Abstract
Resin In Pulp(RIP) is One of the most important processes for separation of uranium from ore while concentration of uranium in ore is low , based on adsorption of uranium that exist in the slurry on onion exchanger resins .uranium ore is dissolved in sulfuric acid and slurry that contain uranium is produced,then this slurry enter stirred reactors and adsorption process is performed.RIP are accepted universally and now adays countries such as canada,south africa and australia use this process when concentration of uranium in slurry after leaching process is 100-500 ppm.in iran also this process is performing in ardacan-saghand mine.Kinetic of adsorption process in stirred reactors has been...
The level set modeling of droplet dynamic in fluid-fluid interaction
, Article 39th AIAA Fluid Dynamics Conference, 22 June 2009 through 25 June 2009, San Antonio, TX ; 2009 ; 9781563479755 (ISBN) ; Mazaheri, I ; Dehkordi, A. M ; Schneider, G. E ; Sharif University of Technology
Abstract
In this work, we present a level set method to simulate steady and unsteady mass transfer from a single droplet moving in a second phase fluid under buoyant force. We initially use level set to determine the interface between the two phases, where the shape of drop forms. Next, we extend this method to solve a unique mass transfer equation for the entire solution domain without considering the discontinuity appeared at the interface. We use a finite element method incorporated with the characteristic-based split (CBS) algorithm to implement axi-symmetric mass transfer equations on a stationary Eulerian grid. Of course, the convection-diffusion modeling of mass transfer is different from the...
Superheated water extraction of catechins from green tea leaves: Modeling and simulation
, Article Scientia Iranica ; Volume 16, Issue 2 C , 2009 , Pages 99-107 ; 10263098 (ISSN) ; Abdollahi Govar, A ; Sharif University of Technology
2009
Abstract
Catechins from fresh green tea leaves as potential sources of anticancer and antioxidant components were target materials in this work. Superheated water extraction, which is a kind of leaching operation, and solvent partition with chloroform and ethyl acetate were utilized to recover Catechins from tea leaves. Then, a mathematical model was developed to simulate the superheated water extraction of Catechins. The unsteady state mass balance of the solute in solid and superheated water phases led to two partial differential equations. The model was solved numerically using a linear equilibrium relationship. The model parameters were predicted applying existing experimental correlations. An...
Dissolution and remobilization of NAPL in surfactant-enhanced aquifer remediation from microscopic scale simulations
, Article Chemosphere ; Volume 289 , 2022 ; 00456535 (ISSN) ; Aminnaji, M ; Rezanezhad, F ; Ghazanfari, M. H ; Babaei, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
In this paper, the dissolution and mobilization of non-aqueous phase liquid (NAPL) blobs in the Surfactant-Enhanced Aquifer Remediation (SEAR) process were upscaled using dynamic pore network modeling (PNM) of three-dimensional and unstructured networks. We considered corner flow and micro-flow mechanisms including snap-off and piston-like movement for two-phase flow. Moreover, NAPL entrapment and remobilization were evaluated using force analysis to develop the capillary desaturation curve (CDC) and predict the onset of remobilization. The corner diffusion mechanism was also applied in the modeling of interphase mass transfer to represent NAPL dissolution as the dominant mass transfer...