scholarly journals Mass Transfer Characteristics of Haemofiltration Modules—Experiments and Modeling

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Alexandra Moschona ◽  
Margaritis Kostoglou ◽  
Anastasios J. Karabelas
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Membrane Fouling ◽  
Transfer Problem ◽  
The Novel ◽  
Reliable Determination ◽  
Diffusive Mass Transfer ◽  
Ill Posed ◽  
Mass Transfer Problem ◽  
Counter Current

Reliable mathematical models are important tools for design/optimization of haemo-filtration modules. For a specific module, such a model requires knowledge of fluid- mechanical and mass transfer parameters, which have to be determined through experimental data representative of the usual countercurrent operation. Attempting to determine all these parameters, through measured/external flow-rates and pressures, combined with the inherent inaccuracies of pressure measurements, creates an ill-posed problem (as recently shown). The novel systematic methodology followed herein, demonstrated for Newtonian fluids, involves specially designed experiments, allowing first the independent reliable determination of fluid-mechanical parameters. In this paper, the method is further developed, to determine the complete mass transfer module-characteristics; i.e., the mass transfer problem is modelled/solved, employing the already fully-described flow field. Furthermore, the model is validated using new/detailed experimental data on concentration profiles of a typical solute (urea) in counter-current flow. A single intrinsic-parameter value (i.e., the unknown effective solute-diffusivity in the membrane) satisfactorily fits all data. Significant insights are also obtained regarding the relative contributions of convective and diffusive mass-transfer. This study completes the method for reliable module simulation in Newtonian-liquid flow and provides the basis for extension to plasma/blood haemofiltration, where account should be also taken of oncotic-pressure and membrane-fouling effects.

Generalized Transient Leveque Problem

1996 ◽  
Vol 61 (9) ◽  
pp. 1267-1284
Author(s):  
Ondřej Wein
Keyword(s):  
Mass Transfer ◽  
Exact Solution ◽  
Shear Rate ◽  
Transfer Problem ◽  
Numerical Data ◽  
Wall Shear Rate ◽  
Response Operator ◽  
Mass Transfer Problem ◽  
Finite Step ◽  
General Response

Response of an electrodiffusion friction sensor to a finite step of the wall shear rate is studied by numerically solving the relevant mass-transfer problem. The resulting numerical data on transient currents are treated further to provide reasonably accurate analytical representations. Existing approximations to the general response operator are checked by using the obtained exact solution.

Parameter Estimation for Dielectric Media Variations Based on the FDTD Method and the Monge–Kantorovich Mass Transfer Problem

2017 ◽  
Vol 53 (6) ◽  
pp. 1-4
Author(s):  
Georgios G. Pyrialakos ◽  
Nikolaos V. Kantartzis ◽  
Tadao Ohtani ◽  
Yasushi Kanai ◽  
Theodoros D. Tsiboukis
Keyword(s):  
Mass Transfer ◽  
Parameter Estimation ◽  
Transfer Problem ◽  
Fdtd Method ◽  
Dielectric Media ◽  
Mass Transfer Problem

On the Monge mass transfer problem

2001 ◽  
Vol 13 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Neil S. Trudinger ◽  
Xu-Jia Wang
Keyword(s):  
Mass Transfer ◽  
Transfer Problem ◽  
Mass Transfer Problem

CFD Simulation of Hydrodynamics, Heat and Mass Transfer Simultaneously in Structured Packing

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
M.R. Khosravi Nikou ◽  
M.R. Ehsani ◽  
M. Davazdah Emami
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Pressure Drop ◽  
Heat And Mass Transfer ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Theoretical Plate ◽  
Absolute Relative Error ◽  
Gas Liquid Flow ◽  
Counter Current

This paper describes the results of computational fluid dynamic modeling of hydrodynamics, heat and mass transfer simultaneously in Flexipac 1Y operated under a counter-current gas-liquid flow condition. The simulation was performed for a binary mixture of methanol-isopropanol distillation. The pressure drop, the height of equivalent to theoretical plate (HETP) and temperature distribution across the column were calculated and compared with experimental data. The mean absolute relative error (MARE) between CFD predictions and experimental data for the pressure drop, HETP and temperature profile are 20.7%, 12.9% and 2.8%, respectively.

scholarly journals Challenges in Modeling Pheromone Capture by Pectinate Antennae

2020 ◽  
Vol 60 (4) ◽  
pp. 876-885 ◽  
Author(s):  
Mourad Jaffar-Bandjee ◽  
Gijs Krijnen ◽  
Jérôme Casas
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Transfer Problem ◽  
Air Flow ◽  
Complex Objects ◽  
Single Sensillum ◽  
Mass Transfer Problem

Synopsis Insect pectinate antennae are very complex objects and studying how they capture pheromone is a challenging mass transfer problem. A few works have already been dedicated to this issue and we review their strengths and weaknesses. In all cases, a common approach is used: the antenna is split between its macro- and microstructure. Fluid dynamics aspects are solved at the highest level of the whole antenna first, that is, the macrostructure. Then, mass transfer is estimated at the scale of a single sensillum, that is, the microstructure. Another common characteristic is the modeling of sensilla by cylinders positioned transversal to the flow. Increasing efforts in faithfully modeling the geometry of the pectinate antenna and their orientation to the air flow are required to understand the major advantageous capture properties of these complex organs. Such a model would compare pectinate antennae to cylindrical ones and may help to understand why such forms of antennae evolved so many times among Lepidoptera and other insect orders.

scholarly journals Some Aspects of Mass Transfer Within the Passages of Fuel Cells

2003 ◽  
Author(s):  
S. B. Beale
Keyword(s):  
Mass Transfer ◽  
Fuel Cells ◽  
Heat Mass Transfer ◽  
Driving Force ◽  
Transfer Problem ◽  
Scalar Transport ◽  
Square Duct ◽  
Mass Transfer Problem

This paper describes a numerical heat/mass transfer analysis for planar and square duct geometries, found in certain fuel cells. Both developing and fully-developed scalar transport are considered. The solution to the heat/mass transfer problem is presented in terms of normalized conductance as a function of the driving force and wall Reynolds/Peclet numbers.

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