Flow Generated by Radial Flow Impellers: PIV Measurements and CFD Simulations

2004 ◽  
Vol 2 (1) ◽  
Author(s):  
Avinash Khopkar ◽  
Joella Aubin ◽  
C Rubio-Atoche ◽  
Catherine Xuereb ◽  
Nathalie Le Sauze ◽  
...  
Keyword(s):  
Low Pressure ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Rushton Turbine ◽  
Image Velocimetry ◽  
Trailing Vortices ◽  
Computational Fluid Dynamics Cfd ◽  
Improved Performance ◽  
Gas Liquid Flow ◽  
Experimental Findings

Particle image velocimetry (PIV) and computational fluid dynamics (CFD) have been used to investigate the single phase and gas-liquid flow generated by a Scaba SRGT turbine. The key details of the trailing vortices, the turbulent flow around the impeller blades and the accumulation of gas have been studied by using PIV measurements and CFD simulations. Both the experimental and numerical results show that the flow and the trailing vortices are not altered significantly upon gassing. The simulated results are generally in good agreement with the experimental findings. The CFD simulations also show that only small low-pressure regions exist behind the blades of the Scaba turbine compared with the very large low-pressure zones formed by the Rushton turbine. These results enable better understanding of the improved performance of the Scaba turbine for gas-liquid dispersions compared with the Rushton turbine.

Experimental and Numerical Flow Visualization in Patient Specific Pre Operative Human Airway Geometry

2011 ◽  
Author(s):  
Mathias Vermeulen ◽  
Cedric Van Holsbeke ◽  
Tom Claessens ◽  
Jan De Backer ◽  
Peter Van Ransbeeck ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Particle Image ◽  
Patient Specific ◽  
Lung Volume Reduction ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Specific Geometry ◽  
Computational Fluid Dynamics Cfd ◽  
Human Airways

An experimental and numerical platform was developed to investigate the fluidodynamics in human airways. A pre operative patient specific geometry was used to create an identical experimental and numerical model. The experimental results obtained from Particle Image Velocimetry (PIV) measurements were compared to Computational Fluid Dynamics (CFD) simulations under stationary and pulsatile flow regimes. Together these results constitute the first step in predicting the clinical outcome of patients after lung surgeries such as Lung Volume Reduction.

CFD Simulations and PIV Measurements for Optimization of Flow Pattern in a Sieve Plate Extraction Column

2011 ◽  
Vol 391-392 ◽  
pp. 1464-1468
Author(s):  
Chang Chun Duan ◽  
Chun Jiang Liu ◽  
Xi Gang Yuan
Keyword(s):  
Flow Pattern ◽  
Reverse Flow ◽  
Continuous Phase ◽  
Extraction Column ◽  
Sieve Plate ◽  
Cfd Simulations ◽  
Flow Area ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd

Present work deals with the optimization for flow pattern of continuous phase in a sieve plate extraction column using both computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. Firstly single-phase simulation was conducted for the traditional column and it was found that there was a very large reverse flow area between every two plates. Then step by step, by changing the downcomer structure, consisting of inclining downcomers, adding baffles, slotting downcomers and baffles and adjusting the number and size of slots, the reverse flow area was decreased and thereby the flow pattern of continuous phase was optimized. Finally, an optimal flow pattern was obtained with reverse flow area greatly reduced. In order to prove the validity of the simulation results, PIV experiments of two columns were carried out and it was found that the results of simulations and experiments are in good agreement.

Numerical Simulation of Biodiesel Production Using Waste Cooking Oil

2013 ◽  
Author(s):  
A. K. M. Mohiuddin ◽  
Nabeel Adedapo Adeyemi
Keyword(s):  
Waste Cooking Oil ◽  
Reynolds Stress Model ◽  
Biodiesel Production ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Dissipation Model ◽  
Computational Fluid Dynamics Cfd ◽  
Experimental Values ◽  
Cfd Method

The goal of this work was to carry out transesterification using computational fluid dynamics (CFD) method and obtain yield comparable to experimental values. First of all, the single–phase flow field was simulated and compared with experimental data obtained by means of particle image velocimetry (PIV) measurements. The velocities calculated from the RSM approach agreed quite well with those from PIV. The CFD simulations of biodiesel production were performed using the Reynolds stress model (RSM) coupled with the eddy dissipation model (EDM). CFD analysis of biodiesel yield compared fairly well with the experimental results available.

scholarly journals Dependence of the Flue Gas Flow on the Setting of the Separation Baffle in the Flue Gas Tract

2021 ◽  
Vol 11 (7) ◽  
pp. 2961
Author(s):  
Nikola Čajová Kantová ◽  
Alexander Čaja ◽  
Marek Patsch ◽  
Michal Holubčík ◽  
Peter Ďurčanský
Keyword(s):  
Particulate Matter ◽  
Flue Gas ◽  
Gas Flow ◽  
Negative Impact ◽  
Combustion Process ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Computational Fluid Dynamics Cfd ◽  
Particle Imaging ◽  
Combustion Of Solid Fuels

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. This article aims to optimize the flue gas tract using separation baffles. This design can make it possible to capture particulate matter by using three baffles and prevent it from escaping into the air in the flue gas. The geometric parameters of the first baffle were changed twice more. The dependence of the flue gas flow on the baffles was first observed by computational fluid dynamics (CFD) simulations and subsequently verified by the particle imaging velocimetry (PIV) method. Based on the CFD results, the most effective is setting 1 with the same boundary conditions as those during experimental PIV measurements. Setting 2 can capture 1.8% less particles and setting 3 can capture 0.6% less particles than setting 1. Based on the stoichiometric calculations, it would be possible to capture up to 62.3% of the particles in setting 1. The velocities comparison obtained from CFD and PIV confirmed the supposed character of the turbulent flow with vortexes appearing in the flue gas tract, despite some inaccuracies.

scholarly journals Numerical simulation of the gas-liquid flow inside a horizontal static mixer

2020 ◽  
Vol 5 (2) ◽  
pp. 1-7
Author(s):  
Ryan Anugrah Putra ◽  
Akhlisa Nadiantya Aji Nugroho
Keyword(s):  
Liquid Flow ◽  
Liquid Velocity ◽  
Superficial Velocity ◽  
Static Mixer ◽  
Cfd Simulations ◽  
Mixing Behavior ◽  
Computational Fluid Dynamics Cfd ◽  
Gas Liquid Flow ◽  
Gas Layer ◽  
Superficial Liquid Velocity

The gas-liquid flow inside a horizontal static mixer was numerically investigated by using Euler-Euler Computational Fluid Dynamics (CFD) simulations. The results confirm that the liquid superficial velocity plays a significant role on the mixing behavior of the gas and liquid. The mixing behavior in this present study at a liquid superficial velocity of 0.2 m/s was the worst both axially and radially. Increasing the liquid superficial velocity significantly improve the mixing between gas and liquid. However, the unwanted gas layer still can be found at the superficial liquid velocity less than 0.8 m/s. A good mixing behavior in this study was achieved at a relatively high velocity (i.e. larger than 0.8 m/s).

Investigation of the Flow Field in a Rectangular Vessel Equipped With a Side-Entering Agitator

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
C. Gómez ◽  
C. P. J. Bennington ◽  
F. Taghipour
Keyword(s):  
Axial Flow ◽  
Limited Attention ◽  
Pulp Fiber ◽  
Fiber Suspensions ◽  
Process Industries ◽  
Piv Measurements ◽  
Stirred Vessels ◽  
Paper Manufacturing ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd

The hydrodynamics of stirred vessels with side-entering impellers, which are used in numerous process industries including petroleum, foods, and pulp and paper manufacturing, have received limited attention. In the present work, the flow in a reduced size rectangular tank equipped with a side-entering axial flow impeller, scaled down from the industrial agitation of low consistency pulp fiber suspensions, was investigated using particle image velocimetry (PIV) and computational fluid dynamics (CFD), in the laminar regime (18≤Re≤120). Tuning of the PIV measuring parameters for an optimum capture of valid velocity vectors within a representative portion of the vessel is described. A detailed description of the construction and refinement of the grid and quantification of the discretization error in the CFD results is also presented. The simulation predictions were extensively evaluated by comparing the measured planar flow patterns and velocity fields at various locations in the mixing vessel. Very good agreement was found between PIV measurements and computed velocities confirming the efficiency of CFD in the analysis of mixing systems. The prediction of global mixing parameters was also evaluated. The computed impeller torque and impeller power number agreed very well with experimental measurements over the range of Re studied.

scholarly journals Experimental and Numerical Study of Blood Flow in μ-vessels: Influence of the Fahraeus–Lindqvist Effect

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 143
Author(s):  
Yorgos G. Stergiou ◽  
Aggelos T. Keramydas ◽  
Antonios D. Anastasiou ◽  
Aikaterini A. Mouza ◽  
Spiros V. Paras
Keyword(s):  
Blood Flow ◽  
Axial Velocity ◽  
Particle Image ◽  
Numerical Study ◽  
Implantable Devices ◽  
Cfd Simulations ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd ◽  
Cell Free Layer

The study of hemodynamics is particularly important in medicine and biomedical engineering as it is crucial for the design of new implantable devices and for understanding the mechanism of various diseases related to blood flow. In this study, we experimentally identify the cell free layer (CFL) width, which is the result of the Fahraeus–Lindqvist effect, as well as the axial velocity distribution of blood flow in microvessels. The CFL extent was determined using microscopic photography, while the blood velocity was measured by micro-particle image velocimetry (μ-PIV). Based on the experimental results, we formulated a correlation for the prediction of the CFL width in small caliber (D < 300 μm) vessels as a function of a modified Reynolds number (Re∞) and the hematocrit (Hct). This correlation along with the lateral distribution of blood viscosity were used as input to a “two-regions” computational model. The reliability of the code was checked by comparing the experimentally obtained axial velocity profiles with those calculated by the computational fluid dynamics (CFD) simulations. We propose a methodology for calculating the friction loses during blood flow in μ-vessels, where the Fahraeus–Lindqvist effect plays a prominent role, and show that the pressure drop may be overestimated by 80% to 150% if the CFL is neglected.

Experimental and Numerical Study of the Flow Around a Semi-Submerged Rectangular Cylinder

2012 ◽  
Author(s):  
Tufan Arslan ◽  
Stefano Malavasi ◽  
Bjørnar Pettersen ◽  
Helge I. Andersson
Keyword(s):  
Particle Image ◽  
Model Simulation ◽  
Numerical Study ◽  
Three Dimensional ◽  
Separated Flow ◽  
Piv Measurements ◽  
Rectangular Cylinder ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd

The present work is motivated by phenomena occurring in the flow field around structures partly submerged in water. A three dimensional unsteady flow around a rectangular cylinder is studied for four different submergence ratios by using computational fluid dynamics (CFD) tools with LES turbulence model. Simulation results are compared to particle image velocimetry (PIV) measurements at Reynolds number Re = 12100 and Froude number Fr = 0.26. Focus in our investigation is on the characterization of the behaviour of vortex structures generated by separated flow. Another target in the study is to obtain better knowledge of the hydrodynamic forces acting on a semi-submerged structure. Computed force coefficients are compared with experimental measurements.

Numerical and Experimental Analysis of Single Phase Jet Interactions

2016 ◽  
Author(s):  
Freddy Hernandez-Alvarado ◽  
Randy Samaroo ◽  
Dinesh V. Kalaga ◽  
Taehun Lee ◽  
Sanjoy Banerjee ◽  
...  
Keyword(s):  
Single Phase ◽  
Tap Water ◽  
Liquid Jets ◽  
Reynolds Stresses ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Mass Transfer Processes ◽  
Image Velocimetry ◽  
Wide Range ◽  
Jet Interactions

Impinging liquid jets have many applications ranging from manufacturing processes to jet propulsion systems. In thermal applications, they are often used in atomization processes to cool the surfaces in extreme heat and mass transfer processes. In the present work, 2-D Particle Image Velocimetry (PIV) measurements have been performed to study the interaction of multiple vertical liquid jets in single-phase flow. A perforated Perspex plate with seven symmetrically placed holes was used to make the liquid jets of degassed tap water. From the PIV measurements, a wide range of liquid jet velocities were investigated, and hydrodynamic parameters such as the instantaneous velocity fields, axial (z) and radial (r) mean and RMS liquid velocities, vorticity, and in-plane Reynolds stresses have been derived. Transient 3-D CFD simulations have also been performed and compared with the experimental data. Good agreement has been found between the experimental and CFD simulations. Further, Reichardt’s hypothesis (1943) has also been examined to better understand the onset of instability for the single-phase multi jet flow.

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