A measurement-integrated solution for particle image velocimetry and volume fraction measurements in a fluidized bed

2013 ◽  
Vol 56 ◽  
pp. 72-80 ◽  
Author(s):  
Jari Kolehmainen ◽  
Jouni Elfvengren ◽  
Pentti Saarenrinne
Keyword(s):  
Particle Image Velocimetry ◽  
Fluidized Bed ◽  
Particle Image ◽  
Volume Fraction ◽  
Image Velocimetry

Key Issues in Measuring the Velocities of Nanoparticles in Nanofluids

2007 ◽  
Vol 364-366 ◽  
pp. 1111-1116 ◽  
Author(s):  
Ming Qian ◽  
Xiao Wu Ni ◽  
Jian Lu ◽  
Zhong Hua Shen
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Laser Speckle ◽  
Experimental Setup ◽  
Particle Volume ◽  
Image Velocimetry ◽  
Speckle Patterns ◽  
Key Issues

Our recent work [1] theoretically revealed that speckles can be formed when nanofluids containing a modest volume fraction of nanoparticles are illuminated by a monochromatic laser beam. This paper focuses on the key issues, including the experimental setup, the particle volume fraction of the nanofluid, the flow velocity of the nanofluid and the diameter of the pipe, in measuring the velocities of nanoparticles in nanofluids with laser speckle velocimetry (LSV). First an experimental setup is established according to the optical characteristics of nanoparticle and the measuring principles of particle image velocimetry (PIV) and LSV. Then a conclusion is made from the experimental results that clear speckle patterns can be formed when the particle volume fraction is between 0.0005% and 0.002% is able to form. Finally, in order to make it applicable to utilize LSV to measure the velocities of nanoparticles in nanofluids that flow in pipe, nanofluids can not flow too fast and the diameter of the pipe should not be too small.

Hydrodynamics of Multiple Jet Systems in a 2D Gas Solid Fluidized Bed

2012 ◽  
Author(s):  
Steven L. Brown ◽  
Brian Y. Lattimer
Keyword(s):  
Fluidized Bed ◽  
Digital Image Analysis ◽  
Particle Image ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Particle Model ◽  
Discrete Particle ◽  
Image Velocimetry ◽  
Discrete Particle Model ◽  
Single Jet

An experimental 2-D fluidized bed was developed to study gas-solid hydrodynamics. The effects of multiple jet systems were examined using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Flow regimes were classified through pressure drop spectral analysis. The combination of these non-intrusive techniques allowed for the development of a solid volume fraction correlation. The experimental results show new void fraction regimes of multiple interacting jets. Jet systems combined to promote gas solid mixing and decrease particle dead zones within the bed. It was determined that the validation of multiple jet Discrete Particle Model simulations cannot be exclusively confirmed from single jet studies.

Influence of Inertial Particles on Turbulence Characteristics in Outer and Near Wall Flow as Revealed With High Resolution Particle Image Velocimetry

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Ammar Saber ◽  
T. Staffan Lundström ◽  
J. Gunnar I. Hellström
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Volume Fraction ◽  
Spherical Particles ◽  
Normal Velocity ◽  
Inertial Particles ◽  
Mean Flow ◽  
Turbulent Characteristics ◽  
Image Velocimetry ◽  
Near Wall

A fully developed turbulent particle-gas flow in a rectangular horizontal channel 100 × 10 × 4000 mm3 is disclosed with high spatial resolution two-dimensional (2D) particle image velocimetry (PIV). The objective is to increase the knowledge of the mechanisms behind alterations in turbulent characteristics when adding two sets of relatively large solid spherical particles with mean diameters of 525 and 755 μm and particle size distributions of 450–600 and 710–800 μm, respectively. Reynolds numbers are 4000 and 5600 and relatively high volume fraction of 5.4 × 10−4 and 8.0 × 10−4 are tested. Both the near wall turbulent boundary layer flow and outer core flow are considered. Results show that the carrier phase turbulent intensities increase with the volume fraction of the inertial particles. The overall mean flow velocity is affected when adding the particles but only to a minor extent. Near the wall, averaged velocity decreases while fluctuating velocity components increase when particles are added to the flow. Quadrant analysis shows the importance of sweep near the wall and ejection events in the region defined by y+ > 20. In conclusion, high inertia particles can enhance turbulence even at relatively low particle Reynolds number <90. In the near bottom wall region, particles tend to be a source of instability reflected as enhancement in rms values of the normal velocity component.

Particle Image Velocimetry of a Swirling Fluidized Bed at Different Blade Angles

2016 ◽  
Vol 39 (6) ◽  
pp. 1151-1160 ◽  
Author(s):  
Shaharin A. Sulaiman ◽  
Chin S. Miin ◽  
Muhammad Y. Naz ◽  
Vijay R. Raghavan
Keyword(s):  
Particle Image Velocimetry ◽  
Fluidized Bed ◽  
Particle Image ◽  
Image Velocimetry
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