Experimental study on liquid flow fields in de-foulant hydrocyclones with reflux ejector using particle image velocimetry

2020 ◽  
Vol 240 ◽  
pp. 116555 ◽  
Author(s):  
Tao Song ◽  
Jinyi Tian ◽  
Long Ni ◽  
Chao Shen ◽  
Yang Yao
2004 ◽  
Vol 126 (5) ◽  
pp. 585-593 ◽  
Author(s):  
Pramote Hochareon ◽  
Keefe B. Manning ◽  
Arnold A. Fontaine ◽  
John M. Tarbell ◽  
Steven Deutsch

In order to bridge the gap of existing artificial heart technology to the diverse needs of the patient population, we have been investigating the viability of a scaled-down design of the current 70 cc Penn State artificial heart. The issues of clot formation and hemolysis may become magnified within a 50 cc chamber compared to the existing 70 cc one. Particle image velocimetry (PIV) was employed to map the entire 50 cc Penn State artificial heart chamber. Flow fields constructed from PIV data indicate a rotational flow pattern that provides washout during diastole. In addition, shear rate maps were constructed for the inner walls of the heart chamber. The lateral walls of the mitral and aortic ports experience high shear rates while the upper and bottom walls undergo low shear rates, with sufficiently long exposure times to potentially induce platelet activation or thrombus formation. In this study, we have demonstrated that PIV may adequately map the flow fields accurately in a reasonable amount of time. Therefore, the potential exists of employing PIV as a design tool.


2018 ◽  
Vol 165 ◽  
pp. 91-106 ◽  
Author(s):  
Chun-yu Guo ◽  
Tie-cheng Wu ◽  
Wan-zhen Luo ◽  
Xin Chang ◽  
Jie Gong ◽  
...  

Author(s):  
Raju Murugan ◽  
Dhanalakshmi Sellan ◽  
Pankaj S. Kolhe

Abstract Two-fluid flow blurring atomization is characterized by the backflow recirculation of the air phase in the liquid pipe by bifurcation of the liquid and airflow. Most of the primary spray process is completed in the injector due to the penetration of air into the liquid tube. Thus, the majority of the liquid ligaments are converted into a fine spray at the outlet of the nozzle. Experiments were performed with two different air to liquid ratios (0.6 and 1) by mass, where water is considered as the liquid and airflow was kept constant (0.2 g/s). To change the ALR, the liquid flow rate was changed. Particle image velocimetry (PIV) diagnostic technique provides the full-field velocity of the spray droplets (discrete phase). It may be noted that sprays are self-seeded and PIV measurements reflect the droplet velocities instead of air velocity. To understand the effect of the spatial resolution of PIV on spray droplet velocity; experiments were conducted at three different spatial resolutions (11.8, 16.4 and 23.22 μm/pixel) for each ALR. As the ALR is increased, the mass of the liquid in the spray decreases, resulting in finer atomization and velocity of the spray droplets. This means that finer droplets are generated for the same mass of air at a lower liquid flow rate as compared to higher liquid flow rate. Note that Reynolds stresses provide an indication of the turbulent breakup of the droplet and larger magnitudes observed for higher ALR indicate finer atomization.


2012 ◽  
Vol 9 (77) ◽  
pp. 3378-3386 ◽  
Author(s):  
Richard J. Bomphrey ◽  
Per Henningsson ◽  
Dirk Michaelis ◽  
David Hollis

Aerodynamic structures generated by animals in flight are unstable and complex. Recent progress in quantitative flow visualization has advanced our understanding of animal aerodynamics, but measurements have hitherto been limited to flow velocities at a plane through the wake. We applied an emergent, high-speed, volumetric fluid imaging technique (tomographic particle image velocimetry) to examine segments of the wake of desert locusts, capturing fully three-dimensional instantaneous flow fields. We used those flow fields to characterize the aerodynamic footprint in unprecedented detail and revealed previously unseen wake elements that would have gone undetected by two-dimensional or stereo-imaging technology. Vortex iso-surface topographies show the spatio-temporal signature of aerodynamic force generation manifest in the wake of locusts, and expose the extent to which animal wakes can deform, potentially leading to unreliable calculations of lift and thrust when using conventional diagnostic methods. We discuss implications for experimental design and analysis as volumetric flow imaging becomes more widespread.


2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Chunlei Shao ◽  
Jianfeng Zhou ◽  
Boqin Gu ◽  
Wenjie Cheng

Particle image velocimetry (PIV) technology was used to study steady and unsteady internal flow fields in a molten salt pump under both internal and external synchronization modes. The velocity fields in the suction chamber, impeller passage and volute were analyzed at different flow rates. The velocity distribution uniformity, velocity weighted average divergent flow angle, and circumferential component of absolute velocity were calculated on the basis of the obtained flow fields. The research is meaningful to the development of molten salt pumps, and the experimental method serves as a reference to similar rotating fluid machinery.


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