Transient Heat and Mass Transfer to a Drop in an Electric Field

1977 ◽  
Vol 99 (2) ◽  
pp. 269-273 ◽  
Author(s):  
F. A. Morrison
Keyword(s):  
Mass Transfer ◽  
Electric Field ◽  
Transfer Rate ◽  
Similarity Transformation ◽  
Fluid Motion ◽  
Sudden Change ◽  
Drop Surface ◽  
Concentration Difference ◽  
Boundary Layer Equations ◽  
Surrounding Fluid

A circulating fluid motion is generated by an electric field imposed on a dielectric drop in another dielectric liquid. The motion of the drop surface may be from the poles to the equator or from the equator to the poles. Transient heat or mass transfer results in response to a sudden change in the temperature difference or concentration difference between the drop and the surrounding fluid. The low Reynolds number, high Peclet number response is analyzed. The boundary layer equations are solved exactly using a similarity transformation. Results are obtained for both directions of circulation. While local fluxes differ greatly when the flow reverses, and despite a lack of symmetry, the overall transfer rate is independent of the direction of flow. This result applies to the transient as well as the steady state.

Mass Transfer During Fluid Sphere Dissolution in an Alternating Electric Field

Volume 3 ◽  
2004 ◽  
Author(s):  
Tov Elperin ◽  
Andrew Fominykh ◽  
Zakhar Orenbakh
Keyword(s):  
Mass Transfer ◽  
Electric Field ◽  
Applied Electric Field ◽  
Fluid Motion ◽  
Analytical Form ◽  
Internal Resistance ◽  
Creeping Flow ◽  
Fluid Sphere ◽  
Droplet Deformation ◽  
Alternating Electric Field

In this study we considered mass transfer in a binary system comprising a stationary fluid dielectric sphere embedded into an immiscible dielectric liquid under the influence of an alternating electric field. Fluid sphere is assumed to be solvent-saturated so that an internal resistance to mass transfer can be neglected. Mass flux is directed from a fluid sphere to a host medium, and the applied electric field causes a creeping flow around the sphere. Droplet deformation under the influence of the electric field is neglected. The problem is solved in the approximations of a thin concentration boundary layer and finite dilution of a solute in the solvent. The thermodynamic parameters of a system are assumed constant. The nonlinear partial parabolic differential equation of convective diffusion is solved by means of a generalized similarity transformation, and the solution is obtained in a closed analytical form for all frequencies of the applied electric field. The rates of mass transfer are calculated for both directions of fluid motion — from the poles to equator and from the equator to the poles. Numerical calculations show essential (by a factor of 2–3) enhancement of the rate of mass transfer in water droplet–benzonitrile and droplet of carbontetrachloride–glycerol systems under the influence of electric field for a stagnant droplet. The asymptotics of the obtained solutions are discussed.

Effect of Quincke Rotation and Taylor Circulation on Mass Transfer from a Fluid Drop in a Constant Electric Field

2011 ◽  
Vol 312-315 ◽  
pp. 259-264
Author(s):  
Tov Elperin ◽  
A. Fominykh
Keyword(s):  
Mass Transfer ◽  
Electric Field ◽  
Similarity Transformation ◽  
Constant Electric Field ◽  
Analytical Form ◽  
Uniform Electric Field ◽  
Two Dimensional ◽  
Convective Mass Transfer ◽  
Fluid Drop ◽  
Quincke Rotation

We consider non-stationary convective mass transfer in a binary system comprising a stationary dielectric two-dimensional fluid drop embedded into an immiscible dielectric liquid under the influence of a constant uniform electric field. The partial differential equation of diffusion is solved by means of a similarity transformation, and the solution is obtained in a closed analytical form. Dependence of Sherwood number vs. the strength of the applied electric field is analyzed. It is shown that an electric field can be used for enhancement of the rate of mass transfer in terrestrial and reduced gravity environments.

Three-Dimensional Unsteady Flow With Heat and Mass Transfer Over a Continuous Stretching Surface

1988 ◽  
Vol 110 (3) ◽  
pp. 590-595 ◽  
Author(s):  
K. N. Lakshmisha ◽  
S. Venkateswaran ◽  
G. Nath
Keyword(s):  
Mass Transfer ◽  
Nodal Point ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Constant Heat Flux ◽  
Stretching Surface ◽  
Boundary Layer Equations ◽  
Self Similar Solution ◽  
Self Similar ◽  
Unsteady Fluid

A numerical solution of the unsteady boundary layer equations under similarity assumptions is obtained. The solution represents the three-dimensional unsteady fluid motion caused by the time-dependent stretching of a flat boundary. It has been shown that a self-similar solution exists when either the rate of stretching is decreasing with time or it is constant. Three different numerical techniques are applied and a comparison is made among them as well as with earlier results. Analysis is made for various situations like deceleration in stretching of the boundary, mass transfer at the surface, saddle and nodal point flows, and the effect of a magnetic field. Both the constant temperature and constant heat flux conditions at the wall have been studied.

scholarly journals Unsteady nano-bioconvective channel flow with effect of nth order chemical reaction

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1011-1024 ◽  
Author(s):  
Md Faisal Md Basir ◽  
Kohilavani Naganthran ◽  
Ehtsham Azhar ◽  
Zaffar Mehmood ◽  
Swati Mukhopadhyay ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Channel Flow ◽  
Chemical Reaction ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Lower Wall ◽  
Layer System ◽  
Boundary Layer Equations ◽  
Order Chemical Reaction

Abstract Nanofluid bioconvective channel flow is an essential aspect of the recent healthcare industry applications, such as biomedical processing systems. Thus, the present work examined the influence of nth order chemical reaction in an unsteady nanofluid bioconvective channel flow in a horizontal microchannel with expanding/contracting walls. The suitable form of the similarity transformation is exercised to transform the governing boundary layer equations into a more straightforward form of system to ease the computation process. The Runge–Kutta method of fifth-order integration technique solved the reduced boundary layer system and generated the numerical results as the governing parameters vary. It is found that the destructive second-order chemical reaction enhances the mass transfer rate at the lower wall but deteriorates the mass transfer rate at the upper wall. The upper channel wall has a better heat transfer rate than the lower wall when the Reynolds number increases.

Free Convective Mass Transfer at Isosceles Triangular Surfaces of Varying Inclination

2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Mass Transfer Process ◽  
Sulfate Solution ◽  
Convective Mass Transfer ◽  
Varying Length ◽  
Inclined Surface ◽  
Vertical Case ◽  
Limiting Diffusion Current

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.

scholarly journals Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou
Keyword(s):  
Mass Transfer ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Two Phase Flow ◽  
Oxygen Transfer Rate ◽  
Flow Patterns ◽  
Oxygen Mass Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

scholarly journals Flow towards a Stagnation Region of a Vertical Plate in a Hybrid Nanofluid: Assisting and Opposing Flows

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 448
Author(s):  
Iskandar Waini ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Radiation Effects ◽  
Vertical Plate ◽  
Similarity Transformation ◽  
Fluid Motion ◽  
Hybrid Nanoparticles ◽  
Problem Solver ◽  
Hybrid Nanofluid ◽  
Al2o3 Nanoparticles ◽  
Nanofluid Flow ◽  
Stagnation Region

This study investigates a hybrid nanofluid flow towards a stagnation region of a vertical plate with radiation effects. The hybrid nanofluid consists of copper (Cu) and alumina (Al2O3) nanoparticles which are added into water to form Cu-Al2O3/water nanofluid. The stagnation point flow describes the fluid motion in the stagnation region of a solid surface. In this study, both buoyancy assisting and opposing flows are considered. The similarity equations are obtained using a similarity transformation and numerical results are obtained via the boundary value problem solver (bvp4c) in MATLAB software. Findings discovered that dual solutions exist for both opposing and assisting flows. The heat transfer rate is intensified with the thermal radiation (49.63%) and the hybrid nanoparticles (32.37%).

Distributed mass transfer rate for modelling the leaching of porous granular materials containing soluble pollutants

2000 ◽  
Vol 55 (7) ◽  
pp. 1257-1267 ◽  
Author(s):  
Tiruta-Barna Ligia ◽  
Barna Radu ◽  
Moszkowicz Pierre ◽  
Bae Hae-Ryong
Keyword(s):  
Mass Transfer ◽  
Granular Materials ◽  
Transfer Rate ◽  
Mass Transfer Rate
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