Flow field characterization in the vicinity of vertical plane electrodes in a bench-scale zinc electrowinning cell

2018 ◽  
Vol 181 ◽  
pp. 103-112 ◽  
Author(s):  
Jin Luo ◽  
PengPeng Jiao ◽  
Ning Duan ◽  
Fuyuan Xu ◽  
Linhua Jiang
Keyword(s):  
Flow Field ◽  
Vertical Plane ◽  
Zinc Electrowinning ◽  
Bench Scale ◽  
Electrowinning Cell

PIV Measurements of Recirculation Patterns in a Stirred Tank

2001 ◽  
Author(s):  
Khaled J. Hammad ◽  
George Papadopoulos
Keyword(s):  
Flow Field ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Vertical Axis ◽  
Transitional Flow ◽  
Piv Measurements ◽  
Vortical Structures ◽  
Blade Passage ◽  
Flow Field Characteristics

Abstract Phase-resolved PIV measurements were performed to reveal the detailed flow features within a triple impeller stirredtank. Two tests were performed: low and high rotational speeds, 175 and 575 RPM, respectively. The tests used an optically transparent mixing vessel to measure the 2D flow field characteristics along a vertical plane passing through the tank center. The measurements disclosed interesting in-plane vortical behavior that when measured at two angular positions with respect to the blade passage further indicated the three-dimensional flow behavior. For the low RPM case, a laminar flow nature was apparent, whereby vortical toroidal structures spanned around the stirrer vertical axis. Six such structures were dominant. For the high RPM case and for θ = 0° six dominant vortical structures were apparent. Their r-z plane location and size were different from that for the low RPM case. With blade passage four of these vortical structures appeared to merge into two, suggesting that constant toroidal vortical structures spanning around the stirrer axis were absent from the high RPM case. A switch between six distinct and four distinct in-plane vortical structures as the blades pass through the measurement plane further suggested a transitional flow field at 575 RPM.

Effects of Density Ratio on the Hydrodynamics of Film Cooling

1990 ◽  
Vol 112 (3) ◽  
pp. 437-443 ◽  
Author(s):  
J. R. Pietrzyk ◽  
D. G. Bogard ◽  
M. E. Crawford
Keyword(s):  
Flow Field ◽  
Film Cooling ◽  
Free Stream ◽  
Laser Doppler Anemometry ◽  
Density Ratio ◽  
Vertical Plane ◽  
Flux Ratio ◽  
Mean Velocity ◽  
Entire Flow ◽  
Hydrodynamic Study

This paper presents the results of a detailed hydrodynamic study of a row of inclined jets issuing into a crossflow with a density ratio of injectant to free stream of 2. Laser-Doppler anemometry was used to measure the vertical and streamwise components of velocity for a jet-to-free stream mass flux ratio of 0.5. Mean velocity components and turbulent Reynolds normal and shear stress components were measured at locations in a vertical plane along the centerline of the jet from 1 diameter upstream to 30 diameters downstream of the jet. The results, which have application to film cooling, give a quantitative picture of the entire flow field, from the approaching flow upstream of the jet, through the interaction region of the jet and free stream, to the relaxation region downstream where the flow field approaches that of a standard turbulent boundary layer.

A Computational Study of the Mixture Preparation in a Direct Injection Hydrogen Engine

2014 ◽  
Author(s):  
Jerome Le Moine ◽  
P. K. Senecal ◽  
Sebastian A. Kaiser ◽  
Victor M. Salazar ◽  
Jon W. Anders ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Computational Study ◽  
Early Stage ◽  
Direct Injection ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Fuel Mixture ◽  
Compression Stroke ◽  
Mixture Preparation

This paper reports the validation of a three-dimensional numerical simulation of the mixture preparation in a direct-injection hydrogen-fueled engine. Computational results from the commercial code CONVERGE are compared to the experimental data obtained from an optically accessible engine. The geometry used in the simulation is a passenger-car sized, four-stroke, spark-ignited engine. The simulation includes the geometry of the combustion chamber as well as the intake and exhaust ports. The hydrogen is supplied at 100 bar from a centrally located injector with a single-hole nozzle. The comparison between the simulation and experimental data is made on the central vertical plane. The fuel mole concentration and flow field are compared during the compression stroke at different crank angles. The comparison shows good agreement between the numerical and experimental results during the early stage of the compression stroke. The penetration of the jet and the interaction with the cylinder walls are correctly predicted. The fuel spreading is under predicted which results in differences in flow field and fuel mixture during the injection between experimental and numerical results. At the end of the injection, the fuel distribution shows some disagreement which gradually increases during the rest of the simulation.

A Model for the Low to Moderate Speed Performance of the Rotating Disk Skimmer

1990 ◽  
Vol 112 (4) ◽  
pp. 476-480 ◽  
Author(s):  
M. S. Christodoulou ◽  
J. T. Turner ◽  
S. D. R. Wilson
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Flow Field ◽  
Water Surface ◽  
Vertical Plane ◽  
Rotating Disk ◽  
Immiscible Liquids ◽  
Hydrodynamic Parameters ◽  
Speed Performance ◽  
Set Up

In an extensive experimental investigation (Christodoulou, 1985) the performance of a disk skimmer rotating in the vertical plane and partially immersed in a liquid has been studied. The aim of the study was to examine the physical and hydrodynamic parameters governing the oil collection rate of the disk when used as one element of a rotating disk skimmer, a device commonly employed to recover oil and similar immiscible liquids from a water surface. This paper presents a theoretical solution for the flow field set up by the disk which has led to an improved understanding of the hydrodynamics of the disk drag-out problem at low to moderate speeds. Experimental data are presented and compared with the theoretical solutions: discrepancies are then explained in terms of departures from the original assumptions.

The orientation of spheroidal microorganisms swimming in a flow field

1987 ◽  
Vol 231 (1262) ◽  
pp. 47-70 ◽  
Keyword(s):  
Flow Field ◽  
Fluid Velocity ◽  
Local Equilibrium ◽  
Vertical Plane ◽  
Unit Vector ◽  
Laboratory Frame ◽  
Spherical Particles ◽  
Falling Sphere ◽  
Dilute Suspensions ◽  
The Stability

This paper shows how to calculate local equilibrium orientations of inhomogeneous spheroidal particles placed in a flow field. The results can be applied either to dilute suspensions of inert particles or to swimming microorganisms; illustrative examples are chosen with the latter appli­cation in mind. The centre of mass of a particle is displaced from the geometric centre C along the axis of symmetry, and the orientation of this axis (represented by the unit vector p ) is determined from the balance between the gravitational couple, non-zero when p is not vertical, and the viscous couple exerted by the surrounding fluid. Fluid and particle inertia are neglected. ‘Local equilibrium’ means that p is stationary in a suitable frame of reference, which may be the laboratory frame or one rotating rigidly relative to it, at the values of fluid velocity, vorticity and rate of strain evaluated at C in the absence of the particle. It is also shown how to determine the stability of local equilibria. Stable equilibrium values of p are calculated explicitly for a number of experimentally realizable flow fields, including vertical Poiseuille flow in a pipe, conical sink flow, two-dimensional straining and shearing flows in a vertical plane, and the wake of a falling sphere. The analysis is particularly simple for spherical particles, when the local rate of strain does not contribute to the viscous couple. The results have implications for laboratory manipulation of the trajectories of swimming algae, and for the develop­ment of collective behaviour and the existence of critical phenomena in suspensions of them.

A Computational Study of the Mixture Preparation in a Direct–Injection Hydrogen Engine

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Jerome Le Moine ◽  
P. K. Senecal ◽  
Sebastian A. Kaiser ◽  
Victor M. Salazar ◽  
Jon W. Anders ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Computational Study ◽  
Early Stage ◽  
Direct Injection ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Fuel Mixture ◽  
Compression Stroke ◽  
Mixture Preparation

This paper reports the validation of a three-dimensional numerical simulation of the mixture preparation in a direct-injection (DI) hydrogen-fueled engine. Computational results from the commercial code CONVERGE are compared to the experimental data obtained from an optically accessible engine. The geometry used in the simulation is a passenger-car sized, four-stroke, and spark-ignited engine. The simulation includes the geometry of the combustion chamber as well as the intake and exhaust ports. The hydrogen is supplied at 100 bar from a centrally located injector with a single-hole nozzle. The comparison between the simulation and experimental data is made on the central vertical plane. The fuel mole concentration and flow field are compared during the compression stroke at different crank angles (CA). The comparison shows good agreement between the numerical and experimental results during the early stage of the compression stroke. The penetration of the jet and the interaction with the cylinder walls are correctly predicted. The fuel spreading is under predicted which results in differences in flow field and fuel mixture during the injection between experimental and numerical results. At the end of the injection, the fuel distribution shows some disagreement which gradually increases during the rest of the simulation.

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