CFD Simulations of the 3D Velocity Profile of Paddle Agitator and Two-blade Impeller in Stirred Vessel with a Highly Viscous Newtonian Fluid

2006 ◽  
Vol 6 (13) ◽  
pp. 2733-2740 ◽  
Author(s):  
M. Bouzit . ◽  
L. Benali . ◽  
M. Hachemi . ◽  
F. Bouzit .
Keyword(s):  
Velocity Profile ◽  
Newtonian Fluid ◽  
Cfd Simulations ◽  
Stirred Vessel

scholarly journals The dam-break problem for concentrated suspensions of neutrally buoyant particles

2013 ◽  
Vol 724 ◽  
pp. 95-122 ◽  
Author(s):  
C. Ancey ◽  
N. Andreini ◽  
G. Epely-Chauvin
Keyword(s):  
Velocity Profile ◽  
Newtonian Fluid ◽  
Velocity Profiles ◽  
Lubrication Theory ◽  
Dam Break ◽  
Particle Migration ◽  
Flow Depth ◽  
Concentrated Suspensions ◽  
Front Position ◽  
Neutrally Buoyant

AbstractThis paper addresses the dam-break problem for particle suspensions, that is, the flow of a finite volume of suspension released suddenly down an inclined flume. We were concerned with concentrated suspensions made up of neutrally buoyant non-colloidal particles within a Newtonian fluid. Experiments were conducted over wide ranges of slope, concentration and mass. The major contributions of our experimental study are the simultaneous measurement of local flow properties far from the sidewalls (velocity profile and, with lower accuracy, particle concentration) and macroscopic features (front position, flow depth profile). To that end, the refractive index of the fluid was adapted to closely match that of the particles, enabling data acquisition up to particle volume fractions of 60 %. Particle migration resulted in the blunting of the velocity profile, in contrast to the parabolic profile observed in homogeneous Newtonian fluids. The experimental results were compared with predictions from lubrication theory and particle migration theory. For solids fractions as large as 45 %, the flow behaviour did not differ much from that of a homogeneous Newtonian fluid. More specifically, we observed that the velocity profiles were closely approximated by a parabolic form and there was little evidence of particle migration throughout the depth. For particle concentrations in the 52–56 % range, the flow depth and front position were fairly well predicted by lubrication theory, but taking a closer look at the velocity profiles revealed that particle migration had noticeable effects on the shape of the velocity profile (blunting), but had little impact on its strength, which explained why lubrication theory performed well. Particle migration theories (such as the shear-induced diffusion model) successfully captured the slow evolution of the velocity profiles. For particle concentrations in excess of 56 %, the macroscopic flow features were grossly predicted by lubrication theory (to within 20 % for the flow depth, 50 % for the front position). The flows seemed to reach a steady state, i.e. the shape of the velocity profile showed little time dependence.

In-Cylinder Flow Correlations Between Steady Flow Bench and Motored Engine Using Computational Fluid Dynamics

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Xiaofeng Yang ◽  
Tang-Wei Kuo ◽  
Orgun Guralp ◽  
Ronald O. Grover ◽  
Paul Najt
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Velocity Profile ◽  
Discharge Coefficient ◽  
Intake Port ◽  
Charge Motion ◽  
Steady State Flow ◽  
Cfd Simulations ◽  
Motored Engine

Intake port flow performance plays a substantial role in determining the volumetric efficiency and in-cylinder charge motion of a spark-ignited engine. Steady-state flow bench and motored engine flow computational fluid dynamics (CFD) simulations were carried out to bridge these two approaches for the evaluation of port flow and charge motion (such as discharge coefficient, swirl/tumble ratios (SR/TR)). The intake port polar velocity profile and polar physical clearance profile were generated to evaluate the port performance based on local flow velocity and physical clearance in the valve-seat region. The measured data were taken from standard steady-state flow bench tests of an intake port for validation of CFD simulations. It was reconfirmed that the predicted discharge coefficients and swirl/tumble index (SI/TI) of steady flow bench simulations have a good correlation with those of motored engine flow simulations. Polar velocity profile is strongly affected by polar physical clearance profile. The polar velocity inhomogeneity factor (IHF) correlates well with the port discharge coefficient, swirl/tumble index. Useful information can be extracted from local polar physical clearance and velocity, which can help for intake port design.

Pipe Flow Measurements of a Transparent Non-Newtonian Slurry

1989 ◽  
Vol 111 (3) ◽  
pp. 331-336 ◽  
Author(s):  
J. T. Park ◽  
R. J. Mannheimer ◽  
T. A. Grimley ◽  
T. B. Morrow
Keyword(s):  
Velocity Profile ◽  
Newtonian Fluid ◽  
Power Law ◽  
Pipe Flow ◽  
Large Scale ◽  
Longitudinal Velocity ◽  
Tangential Velocity ◽  
Turbulent Pipe Flow ◽  
Laser Doppler Velocimeter ◽  
Flow Measurements

An experimental description of the flow structure of non-Newtonian slurries in the laminar, transitional, and full turbulent pipe flow regimes is the primary objective of this research. Experiments were conducted in a large-scale pipe slurry flow facility with an inside pipe diameter of 51 mm. The transparent slurry formulated for these experiments from silica, mineral oil, and Stoddard solvent exhibited a yield-power-law behavior from concentric-cylinder viscometer measurements. The velocity profile for laminar flow from laser Doppler velocimeter (LDV) measurements had a central plug flow region, and it was in agreement with theory. The range of the transition region was narrower than that for a Newtonian fluid. The mean velocity profile for turbulent flow was close to a 1/7 power-law velocity profile. The rms longitudinal velocity profile was also similar to a classical turbulent pipe flow experiment for a Newtonian fluid; however, the rms tangential velocity profile was significantly different.

Determination of the velocity profile of a stream of non-Newtonian fluid

1982 ◽  
Vol 42 (6) ◽  
pp. 618-620
Author(s):  
K. B. Kann ◽  
V. N. Feklistov
Keyword(s):  
Velocity Profile ◽  
Newtonian Fluid

scholarly journals CFD Simulations of Two-Phase Gas/non-Newtonian Fluid Flows in Pipes

2018 ◽  
Author(s):  
Miguel A. Daza Gómez ◽  
Nicolás Ratkovich ◽  
Eduardo Pereyra ◽  
Pietro Poesio
Keyword(s):  
Newtonian Fluid ◽  
Fluid Flows ◽  
Cfd Simulations ◽  
Two Phase

A Mathematical Model for the Laminar Entrance Region of a Newtonian Fluid in a Cylindrical Pipe

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Richard J. Gross ◽  
Nicholas G. Garafolo ◽  
Garrett R. McHugh
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Wall Shear Stress ◽  
Velocity Profile ◽  
Newtonian Fluid ◽  
Axial Velocity ◽  
Entrance Region ◽  
Velocity Data ◽  
Cylindrical Pipe

Abstract This paper develops equations for velocity, pressure drop, and wall shear stress in the entrance or development region of a cylindrical pipe. The model quantifies the velocity and wall shear stress contributions to the entrance region pressure drop and illustrates how data are used to determine the numerical values of parameters needed to complete the model. It assumes a Newtonian fluid, laminar flow, steady-state, and a constant mass density fluid. The fluid axial velocity profile at the entrance region inlet is modeled by an equation that is close to a flat axial velocity and drops off to zero as the radius approaches the wall. The fluid velocity at the entrance region exit is modeled as the axial, fully developed, laminar flow parabolic velocity profile. The inlet velocity profile is multiplied by a decaying function F(x) that is unity at the entrance region inlet and decreases to zero at the entrance region exit. The exit velocity profile is multiplied by a growing function G(x) that is zero at the entrance region inlet and increases to unity at the entrance region exit. The pressure drop through the entrance region is expressed in terms of the wall viscous friction and the change in axial momentum of the fluid. Two mathematical models for F(x) and G(x) are presented. One is more advantageous when pressure drop data and a few centerline velocity data points are available, and the second is more advantageous when only velocity data are available.

Effect of Surfactant Additives on a Boundary Layer on a Flat Plate

2005 ◽  
Author(s):  
Satoshi Ogata ◽  
Takeshi Fujita
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Velocity Profile ◽  
Flat Plate ◽  
Newtonian Fluid ◽  
Surfactant Concentration ◽  
Shape Parameter ◽  
Tap Water ◽  
Number Range ◽  
Surfactant Solutions

The effect of surfactant solutions on the boundary layer over a flat plate has been investigated in the Reynolds number range of approximately Re < 153,000. Experiments were carried out by measuring the velocity profile using a PIV system. Surfactant solutions tested were aqueous solutions of oleyl-bihydroxyethyl methyl ammonium chloride (Ethoquad O/12) in the concentration range of 50 to 500 ppm, to which sodium salicylate was added as a counterion. It was clarified that the boundary layer thickness of surfactant solutions increases significantly near the leading edge comparing with that of tap water, and parallelly develops in that obtained by the Blasius equation. For lower surfactant concentration (50 and 200 ppm) the velocity profile near the wall is distributed between that of laminar flow and turbulent flow for Newtonian fluid. When the Reynolds number increases, the velocity profile gradually increases from the outer edge of the boundary, and approaches the turbulent velocity profile of Newtonian fluid. For higher surfactant concentration (500 ppm), the velocity profile shows large S-shape. The velocity profile does not change very much, even if the Reynolds increases. The shape parameter with surfactant solutions decreases slightly comparing that of tap water at Re < 92,000, The value of shape parameter H with surfactant solution shows 1.66 < H < 2.32.

CFD and Experiment Investigation of the Mixing Characteristics of Non-Newtonian Fluids in a Stirred Vessel

2018 ◽  
Author(s):  
Peng Wang ◽  
Thomas Reviol ◽  
Haikun Ren ◽  
Martin Böhle
Keyword(s):  
Reynolds Stress ◽  
Newtonian Fluid ◽  
Cfd Simulation ◽  
Rotation Speed ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Operating Conditions ◽  
Newtonian Fluids ◽  
Stress Model ◽  
Stirred Vessel

The mixing performance of a novel design propeller fixed at a position with the angle of −10° combine the inference of the variety of rotation speed and rheology properties were investigated using an ultrasonic Doppler anemometer (UDA) and CFD simulation to investigate the flow patterns and the power consumption in a mixing vessel. The fluids of interest in this research are CMC fluids, which is a type of Walocel CRT 40,000PA powder was added into water to prepare the solutions with the mass concentration which performed shear thinning non-Newtonian fluid properties. As the viscosity of the non-Newtonian fluids varies from the shear rate, rather than a constant value. Therefore, a non-Newtonian power-law model has been selected to describe the properties of the non-Newtonian fluids, and combine with six turbulence models (the standard k-ω model, RNG k-ε, standard k-ε, Realizable k-ε, SST k-ω and Reynolds stress model (RSM))for mechanical agitation of non-Newtonian fluids. Through comparing experiment results, the SST k-ω and Reynolds stress model (RSM) are found more physical than other turbulence models at the design operating point. Furthermore, the CFD simulation results from Reynolds stress model (RSM) and the SST models were validated with the experimental results over the range of rotation speed (small, design, and large rotation speeds), and show that the simulated propeller torque and flow patterns agreed very well with experimental measurements. The velocity field distribution with different operating conditions within selected planes also have been compared with each other and found that for different rheology concentrations and operating conditions, the turbulence model should be properly chosen. The model for simulating non-Newtonian fluid in a stirred vessel in this study can lay a foundation for further optimum research.

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