The Clogging Behavior of a Vortex Pump: An Experimental Study on the Influence of Impeller Designs

Author(s):  
Angela Gerlach ◽  
Dorian Perlitz ◽  
Flemming Lykholt-Ustrup ◽  
Christian Brix Jacobsen ◽  
Paul Uwe Thamsen

This paper analyzes the clogging behavior of a vortex pump with different impeller designs. The influence of blade outlet angle, blade number, and impeller diameter were tested. Non-woven textiles in different concentrations served as the clogging material. The results suggest that a smaller outlet blade angle, a higher blade number, and a larger impeller diameter allow pumping more textiles. Impellers that were capable of pumping more textiles, however, were less efficient. Overall, pumping textiles causes efficiency losses. However, this could not be only related to increased power consumption. Flow rates under clogging operation were close to the flow rates under clear water operation irrespective of the amount of clogging material and the impellers design. Further, in all tests clogging material accumulated at the suction mouth in the casing.

Author(s):  
Fakhar Muhammad Abbas ◽  
Usman Ali Naeem ◽  
Usman Ghani ◽  
Amina Khan ◽  
Talat Farid Ahmad

The bridges are one of important structures in any country. The failure of bridges occurs due to many factors including design flaws and manufacturing construction errors. Among all imperfections scouring around the pier is the most detrimental. So, the estimation of local scouring around a bridge pier is of fundamental importance for the safe design of bridges. Although numerous researches have been done on local scouring around a single bridge pier. The present study investigates the effect of angle of inclination of dual bridge pier configuration on local scouring around bridge piers. Principally rectangular shaped dual bridge piers were installed in sand bed of laboratory flume at angle of inclination of 0°,7°,12°,15° and 19° with vertical respectively. Three different flow rates 9, 14 and 18L/sec were considered during each trial. The duration of each trial was kept around 2 hours. The scour depth was measured separately around both piers with the help of point gauge under clear water condition. The value of scour depth around upstream pier was larger as compared to downstream pier because of the lower strength of horseshoe vortices around downstream pier. From the experimental results, it can be concluded that there is an inverse relationship between the angle of inclination and scour depth, an increase in the angle of inclination leads to decrease in scour depth around both piers. The value of scour depth was maximum when piers were at 0° and minimum at 19°. It was also found that scour depth increases with the increase in flow rate.


2013 ◽  
Vol 724-725 ◽  
pp. 476-479
Author(s):  
Yao Hui Geng ◽  
Dan Yu ◽  
Jiang Lv

This paper presents a multi-functional wind power generation apparatus, which is suitable for doing fundamental experiment in university laboratories. The laboratorial apparatus has features of being stable, visualized and convenient in exhibiting the entire process of wind power conversion and its utilization. Moreover, the experimental device can display the relationships between its output powers and several characteristic parameters, including wind speed, blade number, wings shape, wings length, pitch angle, load and tip-speed ratio, etc. The wind wheels adjustable performance was emphasized by changing the blade length, blade angle and blade number within the same hub. The wind power generation apparatus provides various options for many experimental projects and corresponding experimenters. Meanwhile, it meets different levels of experimental teaching requirements.


Author(s):  
Dr. Mazhar Hussain

The hydrodynamic characteristics of mixing fluids are always the points to consider in improvement of their mixing quality especially using motionless mixers normally stated as “Static Mixers”. Motionless mixing technique was adopted for Air-Water system with the advantage of negligible power consumption over dynamic mixers. Different hydrodynamic characteristics were experimented using “Baffle Type” static element and were compared to those of already used in recent studies. Dissolved oxygen content, Static mixer geometry (i.e. Baffle, Blade, Wheel, Plate and Needle), mixing fluids flow rates were chosen as variables and selected in this content as rate of mass transfer study which founds out to be significant using “Baffle Type” static element. Volumetric mass transfer was also achieved at higher scale which gives a clear indication of increase the mass transfer coefficient in between the comparison of “Baffle type” element and other mentioned elements. Pressure droplet and depletion in Air bubble size across static elements were visually perceived using Hg-Manometer and still photography respectively. A mathematical model was also developed portraying the Air bubble diameter at different flow rates for this system. Other hydrodynamics like higher Dissolved Oxygen (DO) Content, Less Power consumption were also found to be more advantageous for “Baffle Type” static element.


1992 ◽  
Vol 114 (2) ◽  
pp. 454-461 ◽  
Author(s):  
S. H. Bhavnani ◽  
J. M. Khodadadi ◽  
J. S. Goodling ◽  
J. Waggott

Results are presented for an experimental study of fluid flow in models of gas turbine disk cavities. Experiments were performed on 70-cm-dia disks for rotational Reynolds numbers up to 2.29 × 106. Velocity and pressure distributions are presented and compared to previous theoretical and experimental studies for a free disk, and an unshrouded plane Rotor–Stator disk system. Minimum coolant flow rates for the prevention of ingress, determined for the case of a simple axial rim seal, compare well with previously published data.


2014 ◽  
Vol 14 (03) ◽  
pp. 1450045
Author(s):  
HUACHUN WU ◽  
GAO GONG ◽  
ZHIQIANG WANG ◽  
YEFA HU ◽  
CHUNSHENG SONG

Hydraulic performance is an especially important factor for maglev axial blood pumps that have been used in patients with heart disease. Most maglev axial blood pumps basically consist of a straightener, an impeller and a diffuser. The diffuser plays a key role in the performance of the maglev axial blood pump to provide an adequate pressure head and increase the hydraulic efficiency. Maglev axial blood pumps with various structural diffusers exhibit different hydraulic performance. In this study, computational fluid dynamics (CFD) analysis was performed to quantify hydrodynamic in a maglev axial blood pump with a flow rate of 6 L/min against a pressure head of 100 mmHg to optimize the diffuser structure. First, we design the prototype of diffuser structure based on traditional design method, establish blood flow channel models using commercial software ANSYS FLUENT. Specifically, compare the performance of pump with the diffusers of different parameters, such as the leading edge blade angle, blade-thickness and blade-number. The results show that the diffuser structures with the thickening blade by arc airfoil law, blade-number of 6, leading edge blade angle of 24°, and trailing edge blade angle of 90° exhibited the best hydraulic performance which could be utilized in the optimization design of maglev axial blood pumps.


1988 ◽  
Vol 41 (4) ◽  
pp. 623
Author(s):  
MJ O'Keefe ◽  
JLA Francey

An experimental study of flat-plate solar collectors using ethylene, propylenediene monomer (EPDM) absorber plates is descn"bed. In spite of the high thermal resistance of this material the performance is found to compare well with metal absorbers and to be in agreement with the Hottel-Whillier-Bliss equation. There is, however, an observed increase in the heat loss coefficient for mass flow rates below a critical value.


2016 ◽  
Vol 78 (5-3) ◽  
Author(s):  
Duratul Ain Tholibon ◽  
Junaidah Ariffin ◽  
Jazuri Abdullah ◽  
Juliana Idrus

A large number of studies both theoretical and experimental have been devoted to understand the physical mechanisms underlying the bar formation. This can be investigated by carrying out an experimental work in an erodible sand bed channel using a large-scale physical river model. The study included the various hydraulic characteristics with steady flow rates and sediment supply. An experimental work consists of four matrices of flow rate and channel width with other variables namely grains size and bed slope were kept constant. Details of bar profile development that generated using Surfer, a software used for 3D elevation plots are included.


1973 ◽  
Vol 60 (2) ◽  
pp. 241-255 ◽  
Author(s):  
F. T. Smith

An experimental study of distributed air-injection from a porous section of a flat plate into a uniform incompressible airflow is described. The relative mass flow rates of the injection varied between 0·008 and 0·053 (strong injection) and the blowing was fairly uniformly distributed. In the resulting flow field, which was predominantly laminar except near the dividing streamline, where unsteadiness prevailed, velocity profile and pressure measurements were taken and the position of the dividing streamline thereby estimated. Overall the results agree fairly well with the steady laminar theory for strong normal blowing, outlined in §2, although for the strongest blow some signs of separation some way upstream of the blow are apparent.


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