scholarly journals Preliminary tests of particle image velocimetry for the upper plenum of a scaled model of a very high temperature gas cooled reactor

2015 ◽  
Vol 83 ◽  
pp. 305-317 ◽  
Author(s):  
Kyle L. McVay ◽  
Jae-Hyung Park ◽  
Saya Lee ◽  
Yassin A. Hassan ◽  
N.K. Anand
Keyword(s):  
Particle Image Velocimetry ◽  
High Temperature ◽  
Particle Image ◽  
Scaled Model ◽  
Image Velocimetry ◽  
Very High ◽  
High Temperature Gas

Flow Visualization in the Scaled Up Pebble Bed of High Temperature Gas-Cooled Reactor Using Particle Image Velocimetry Method

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Jae-Young Lee ◽  
Sa-Ya Lee
Keyword(s):  
Particle Image Velocimetry ◽  
High Temperature ◽  
Flow Field ◽  
Hot Spots ◽  
Particle Image ◽  
Pebble Bed ◽  
Stagnation Points ◽  
Image Velocimetry ◽  
Particle Image Velocimetry Method ◽  
High Temperature Gas

The flow visualization in the complicated flow geometry of the pebble bed of the high temperature gas-cooled reactor is investigated to identify the stagnation points at which internal hot spots are expected. A particle image velocimetry method was employed to visualize flow for the pebble bed in the structure of the face centered cubic. The wind tunnel was designed to provide the same Reynolds number of 2.1614×104 as the pebble bed nuclear reactor. Scaling law determined the diameter of the pebble as 120 mm, which is two times bigger than the reference when we use air as a coolant rather than helium. The present scaled up design reduces the load of high speed imaged acquisition and the flow field measured by 4000 frames/s. It was found that the present method identified flow field successfully, including the stagnation points suspected to produce hot spots on the surface of the pebble bed. The present data are useful in evaluating the three-dimensional computational fluid dynamics analysis.

Study of Ultrasonically-Induced Fluid Flows Using Micro-Particle Image Velocimetry

2007 ◽  
Author(s):  
Heiko van der Linden ◽  
Ralph Lindken ◽  
Jerry Westerweel
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Pressure Fluctuations ◽  
Fluid Flows ◽  
High Shear ◽  
Shear Forces ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry ◽  
Flow Phenomena ◽  
Very High

This paper describes our recently started research into the flow phenomena that occur in microchannels and microcavities during ultrasonic agitation. With micro-particle image velocimetry we have seen rapidly changing flows together with the occurrence of cavitation events. Both these processes suggest that very high shear forces are present in the solution in combination with rapidly changing pressure fluctuations. The research presented here is of importance for the design of ultrasonic mixers and ultrasonic cell lysis devices.

Particle Image Velocimetry Measurements of Tornado-Like Flow Field in Model WindEEE Dome

2014 ◽  
Author(s):  
Maryam Refan ◽  
Horia Hangan ◽  
Kamran Siddiqui
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Radial Velocity ◽  
Particle Image ◽  
Tangential Velocity ◽  
Scaled Model ◽  
Energy And Environment ◽  
Radial Profiles ◽  
Image Velocimetry ◽  
Wide Range

The flow field of tornado vortices simulated in the 1/11 scaled model of the Wind Engineering, Energy and Environment (WindEEE) Dome is characterized. Particle Image Velocimetry measurements were performed to investigate the flow dynamics for a wide range of Swirl ratios (0.12≤S≤1.29) and at various heights above the surface. It is shown that this simulator is capable of generating a wide variety of tornado like vortices ranging from a single-celled laminar vortex to a multi-celled turbulent vortex. Radial profiles of the tangential velocity demonstrated a clear variation in the experimental values with height at and after the touch-down of the breakdown bubble. Also, the comparison between experimental tangential velocities and the Rankine model estimations resulted in good agreement at only the upper levels (Z>0.35). Radial velocity values close to the surface rose as the swirl increased which is mainly due to the intensified tangential velocities in that region. In addition, variation of the radial velocity with height is more noticeable for higher swirls which can be explained by the flow regime being fully turbulent for S≥ 0.57.

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