Measurement of the Periodic Flow Field in a Radial Diffuser Pump by the PIV-Method

2007 ◽  
Author(s):  
Friedrich-Karl Benra ◽  
Jianjun Feng ◽  
Hans Josef Dohmen
Keyword(s):  
Particle Image ◽  
Flow Measurements ◽  
Piv Method ◽  
Diffuser Flow ◽  
Image Velocimetry ◽  
Impeller Outlet ◽  
Rear Part ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Inflow Conditions

Detailed flow measurements are conducted by two-dimensional Particle Image Velocimetry (PIV) in a low specific speed radial diffuser pump at the design operating point, in order to investigate the impeller-diffuser interaction. The measurements are conducted at midspan for different relative positions between the impeller and diffuser. The measuring region covers a complete impeller channel and also a complete diffuser channel. The analysis of the experimental results shows that a jet-wake structure is observed near the impeller outlet. The presence of the diffuser vanes mainly affects the impeller flow at the rear part near the impeller outlet. The diffuser flow strongly depends on the relative impeller position which provides different inflow conditions for the diffuser.

Time-Resolved Particle Image Velocimetry (PIV) Measurements in a Radial Diffuser Pump

2009 ◽  
Author(s):  
Jianjun Feng ◽  
Friedrich-Karl Benra ◽  
Hans Josef Dohmen
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Time Resolved ◽  
Piv Measurements ◽  
Part Load ◽  
Channel Characteristic ◽  
Image Velocimetry ◽  
Pump Stage ◽  
Low Specific Speed ◽  
Load Conditions

The truly time-variant unsteady flow in a low specific speed radial diffuser pump stage has been investigated by time-resolved Particle Image Velocimetry (PIV) measurements. The measurements are conducted at the midspan of the blades for the design condition and also for some severe part-load conditions. The instantaneous flow fields among different impeller channels are analyzed and compared in detail, and more attention has been paid to flow separations at part-load conditions. The analysis of the measured results shows that the flow separations at two adjacent impeller channels are quite different at some part-load conditions. The separations generally exhibit a two-channel characteristic.

scholarly journals Study of Deformation and Breakup of Submillimeter Droplets’ Spray in a Supersonic Nozzle Flow

2020 ◽  
Vol 10 (18) ◽  
pp. 6149
Author(s):  
Oleg A. Gobyzov ◽  
Mikhail N. Ryabov ◽  
Artur V. Bilsky
Keyword(s):  
High Speed ◽  
Particle Image ◽  
Supersonic Nozzle ◽  
Stress Effect ◽  
Size Distributions ◽  
Flow Measurements ◽  
Image Velocimetry ◽  
Accelerated Flow ◽  
High Speed Flows ◽  
Breakup Mode

The problem of secondary atomization of droplets is crucial for many applications. In high-speed flows, fine atomization usually takes place, and the breakup of small droplets determines the final products of atomization. An experimental study of deformation and breakup of 15–60 µm size droplets in an accelerated flow inside a converging–diverging nozzle is considered in the paper. Particle image velocimetry and shadow photography were employed in the experiments. Results of gas and liquid phase flow measurements and visualization are presented and analyzed, including gas and droplets’ velocity, shape and size distributions of droplets. Weber numbers for droplets’ breakup are reported. For those small droplets at low Weber numbers, the presence of well-known droplets’ breakup morphology is confirmed, and rare “pulling” breakup mode is detected and qualitatively described. For the “pulling” breakup mode, a consideration, explaining its development in smaller droplets through shear stress effect, is provided.

scholarly journals Comparison of Periodic Flow Fields in a Radial Pump among CFD, PIV, and LDV Results

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Jianjun Feng ◽  
F.-K. Benra ◽  
H. J. Dohmen
Keyword(s):  
Unsteady Flow ◽  
Laser Doppler Velocimetry ◽  
Particle Image ◽  
Velocity Fields ◽  
Image Velocimetry ◽  
Rotating Impeller ◽  
Low Specific Speed ◽  
Radial Pump ◽  
Comparison Of The Results ◽  
Better Than

The interaction between the impeller and the diffuser is considered to have a strong influence on the unsteady flow in radial pumps. In this paper, the unsteady flow in a low specific speed radial diffuser pump has been simulated by the CFD code CFX-10. Both Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV) measurements have been conducted to validate the CFD results. Both the phase-averaged velocity fields and the turbulence fields obtained from different methods are presented and compared, in order to enhance the understanding of the unsteady flow caused by the relative motion between the rotating impeller and the stationary diffuser. The comparison of the results shows that PIV and LDV give nearly the same phase-averaged velocity fields, but LDV predicts the turbulence much clearer and better than PIV. CFD underestimates the turbulence level in the whole region compared with PIV and LDV but gives the same trend.

scholarly journals Flow Measurements in a Blood-Perfused Collagen Vessel Using X-Ray Micro-Particle Image Velocimetry

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e81198 ◽  
Author(s):  
Elizabeth Antoine ◽  
Cara Buchanan ◽  
Kamel Fezzaa ◽  
Wah-Keat Lee ◽  
M. Nichole Rylander ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Flow Measurements ◽  
X Ray ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry

scholarly journals Application of particle image velocimetry (PIV) to measure the displacement of sandy soil in laboratory

2021 ◽  
Vol 63 (3) ◽  
pp. 70-77
Keyword(s):  
Grain Size ◽  
Particle Image Velocimetry ◽  
Sandy Soil ◽  
Laboratory Tests ◽  
Particle Image ◽  
Degree Of Saturation ◽  
Grain Sizes ◽  
Piv Method ◽  
Soil Displacement ◽  
Image Velocimetry

Particle image velocimetry (PIV) has been heavily used to measure the displacement and flow velocity in fluid mechanics. However, applications of this method to determining soil displacement in geotechnical laboratory tests are rare. This paper aims to verify the applicability of this method in determining the displacement of sandy soil under different saturation conditions and soil grain sizes. The results showed that this method could effectively determine soil displacement with an accuracy of 0.13 mm. Furthermore, the degree of saturation of soil did not influence the PIV results whereas the homogeneity of soil, as indicated by grain size distribution, reduced the precision of the PIV method.

Infrared Micro-Particle Image Velocimetry of Fluid Flow in Silicon-Based Microdevices

Volume 4 ◽  
2004 ◽  
Author(s):  
Dong Liu ◽  
Suresh V. Garimella ◽  
Steve T. Wereley
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Capillary Tube ◽  
Surface Flow ◽  
Mems Devices ◽  
Flow Measurements ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Image Velocimetry ◽  
Silicon Based

A non-intrusive diagnostic technique, infrared micro-particle image velocimetry (IR-PIV), is developed for measuring flow fields within MEMS devices with micron-scale resolution. This technique capitalizes on the transparency of silicon in the infrared region, and overcomes the limitation posed by the lack of optical access with visible light to sub-surface flow in silicon-based micro-structures. Experiments with laminar flow of water in a circular micro-capillary tube of hydraulic diameter 255 μm demonstrate the efficacy of this technique. The experimental measurements agree very well with velocity profiles predicted from laminar theory. Cross-correlation and auto-correlation algorithms are employed to measure very-low and moderate-to-high velocities, respectively; the former approach is suitable for biomedical applications while the latter would be needed for measurements in electronics cooling. The results indicate that the IR-PIV technique effectively extends the application of regular micro-PIV techniques, and has great potential for flow measurements in silicon-based microdevices.

scholarly journals Comparison of energy parameters of a centrifugal pump with a multi-piped impeller in cooperation either with an annular channel and a spiral channel

2018 ◽  
Vol 8 (1) ◽  
pp. 513-522 ◽  
Author(s):  
Bartłomiej Chomiuk ◽  
Janusz Skrzypacz
Keyword(s):  
Centrifugal Pump ◽  
Annular Channel ◽  
Operating Parameters ◽  
Centrifugal Pumps ◽  
Impeller Outlet ◽  
Flow Geometry ◽  
Quantitative Verification ◽  
Flow Through ◽  
Low Specific Speed ◽  
Specific Speed

Abstract The article presents results of numerical analyzes, which raise a subject of influence of the cooperation the multi-piped impeller with a rationalized flow geometry of annular casing and volute casing for liquid flow through centrifugal pump and their operating parameters in the extremely low specific speed nq<10. The multi-piped impeller (patented by authors) is a major alternative to classic vane impellers. The stator type is responsible for the conversion of the kinetic energy of the liquid by the impeller outlet into potential energy, which determines the overall efficiency of the pump. Also, the article presents qualitative and quantitative verification of results obtained by computer modeling and an attempt to estimate their accuracy. The article focuses mainly on the comparison of the performance parameters of the pump with a multi-piped impeller in cooperation with two stator types with a rationalized flow geometry. Both outlet elements were tested in various configurations of constructional features. The complexity of the construction of the stator can significantly affect the manufacturing costs of pump unit. Knowledge concerning construction of hydraulic elements of centrifugal pumps working in the range of parameters corresponding specific speed (nq<10) is insufficient. As shown in the paper, the annular type casing model pump cooperating with a multi-piped impeller, designed in accordance with literature, reached far poorer operating parameters than the rational annular construction in a configuration with the same impeller.

Particle image velocimetry: simultaneous two-phase flow measurements

1996 ◽  
Vol 7 (9) ◽  
pp. 1270-1280 ◽  
Author(s):  
M L Jakobsen ◽  
W J Easson ◽  
C A Greated ◽  
D H Glass
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Measurements ◽  
Image Velocimetry
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