Study of coefficient of discharge through orifices

2021 ◽  
Author(s):  
Ajay Wadhwa
Keyword(s):  
Coefficient Of Discharge

Culvert inlet efficiency

1995 ◽  
Vol 22 (3) ◽  
pp. 611-616 ◽  
Author(s):  
C. D. Smith ◽  
A. G. Oak
Keyword(s):  
Key Words ◽  
Experimental Work ◽  
Control Efficiency ◽  
Head Losses ◽  
Coefficient Of Discharge ◽  
The University

The results of experimental work carried out on culvert inlet efficiency at the University of Saskatchewan are reported in this paper. Efficiency is reported in terms of coefficient of discharge when the culvert operates with inlet control, and in terms of the coefficient of entrance loss when the culvert operates with outlet control. A larger coefficient of discharge or a smaller coefficient of entrance loss represents a higher efficiency. Seven different culvert inlets were tested for both inlet and outlet control, and for the headwater level both above and below the elevation of the crown of the pipe at the inlet. The results are reported in nondimensional charts. Key words: culvert flow, inlet control, outlet control, efficiency, head losses, capacity.

Theoretical and experimental study of motion and sinking time of Saxon Bowls

2022 ◽  
Author(s):  
Jaikumar Sankar ◽  
Liu Yang
Keyword(s):  
Motion Tracking ◽  
Volumetric Flow Rate ◽  
Free Form ◽  
Motion Path ◽  
Time Interval ◽  
Flow Profile ◽  
Bernoulli’S Equation ◽  
Hole Radius ◽  
Coefficient Of Discharge ◽  
High Degree

Abstract This work focuses on investigating the time of sinking of a Saxon bowl proposed by ‘International Young Physicists’ Tournament in 2020. A quasi-static model is built to simulate the motion path of the bowl and predict the sinking time subsequently. The model assumes an open axisymmetric bowl with a hole in its base. The hole is modelled as a pipe for which the flow profile is governed by a modified Bernoulli’s equation which has a Coefficient of Discharge (C_d) added to account for energy losses. The motion of the entire bowl is assumed to be in quasi-static equilibrium for an infinitesimal time interval to calculate the volumetric flow rate through the hole. The model is used to predict the sinking times of various bowls against independent variables - hole radius, bowl dimensions, mass of bowl, mass distribution of bowl, and Coefficient of Discharge - and predict the motion path of bowls of different, axisymmetric geometries. Characterisation of C_d was done by draining a bowl filled with water and measuring the time taken to do so. Experimental verification was completed through measuring sinking times of 3D printed hemispherical bowls of the different variables in water. Motion tracking of bowls with different geometries was done using computational pixel tracking software to verify the model’s predictive power. Data from experiments for sinking time against the variables corroborate with the model to a great degree. The motion path tracked, matched the modelled motion path to a high degree for bowls of different shapes, namely a hemisphere, cylinder, frustum, and a free-form axisymmetric shape. The work is poised for an undergraduate level of readership.

scholarly journals Performance Advantages of Labyrinth Weir

2019 ◽  
Vol 9 (2S2) ◽  
pp. 26-29
Keyword(s):  
Control Flow ◽  
Water Bodies ◽  
Labyrinth Weir ◽  
Common Structure ◽  
Water Courses ◽  
Coefficient Of Discharge ◽  
Labyrinth Weirs

Weir is a very common structure across water courses to control flow and to release surplus water from water bodies. Simple straight weirs are less efficient compared to labyrinth weir where the weir length is increased by folds. In this research, experiments were conducted in the laboratory to find the increase in discharge due to labyrinth or decrease in coefficient of discharge due to labyrinth. Further two labyrinth weirs were analyzed to understand the efficiency with respect to the shape of the labyrinth weir. Compared to the ogee weir, the labyrinth weir discharges more water (more than 60%) for the same head of flow.

scholarly journals Influence of twisted tape insert on the coolant flow characteristics in swirled film cooling

2021 ◽  
pp. 259-259
Author(s):  
Vashista Ademane ◽  
Ravikiran Kadoli ◽  
Vijaykumar Hindasageri
Keyword(s):  
Film Cooling ◽  
Flow Characteristics ◽  
Coolant Flow ◽  
Twisted Tape ◽  
Pumping Power ◽  
Pressure Losses ◽  
Jet Trajectory ◽  
Swirl Intensity ◽  
Cooling Behavior ◽  
Coefficient Of Discharge

The Present paper discusses film cooling behavior through numerical simulation in the presence of a twisted tape insert inside the film hole. The twisted tape insert imparts a swirl to the coolant flow. Coolant swirl intensity is controlled by varying the pitch of the twisted tape resulting in swirl numbers (S) of 0.0289, 0.116 and 0.168. The film cooling performance is evaluated using area-averaged effectiveness and heat transfer coefficient for blowing ratios of 0.5, 1.0, 1.5 and 2.0. Results revealed a significant amount of improvement in averaged effectiveness with the addition of swirl. Coolant swirl predominantly modifies the jet trajectory resulting in a reduced jet penetration and increased lateral expansion. Further investigation on the effect of twisted tape thickness on the coolant distribution has been found to be negligible. Pressure losses occurring due to the insertion of twisted tape inside the film hole is evaluated through the coefficient of discharge which indicated the necessity of higher pumping power than the film cooling case with no-swirl.

A New Method for Performance Measurement of PPV Fans for Fire Fighting Under Realistic Conditions

2020 ◽  
Author(s):  
Michael Steppert ◽  
Philipp Epple ◽  
Michael Steber ◽  
Stefan Gast
Keyword(s):  
Design Process ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Navier Stokes ◽  
Analytical Relation ◽  
Positive Pressure ◽  
Flow Rates ◽  
Free Jet ◽  
Actual Flow Rate ◽  
Coefficient Of Discharge

Abstract PPV Fans (Positive Pressure Ventilation Fans) are used in firefighting to remove smoke from a burning building, so that fire fighters can have a clear view inside the house and injured people do not have to breathe toxic smoke. This can be done by placing a PPV fan in a distance of about two meters in front of a door of the burning building. On another, carefully chosen position in the building, e. g. a window, a door or at the roof an opening has to be created, where the smoke can leave the building. The same volumetric flow rate of gas that is blown into the building by the PPV fan has to leave the building at a chosen opening. Because the gas entering the building is air and the gas leaving the building is a mixture of smoke and air, the smoke concentration in the building can be reduced. To test the performance of such PPV fans, a test building with a door in the first floor and a window in the 3rd floor has been built. To measure the volumetric flow rate of the smoke and air mixture through the window in the 3rd floor that is leaving the building, a flow meter nozzle was designed. The design process was done using the commercial Navier Stokes solver Star CCM+, where three nozzle designs, such as a nozzle with constant velocity increase, a quarter circle nozzle and a non-curved nozzle were investigated for different volumetric flow rates. Also, a rounding at the window, where the nozzle is placed, was investigated to prevent flow detachment and shock losses at the inlet of the nozzle. The volumetric flow rate through the nozzle can be calculated, by measuring the pressure at the nozzle wall (before the contraction) and applying Bernoulli’s law, the continuity equation and assuming atmospheric pressure at the free jet flow at the end of the nozzle. The so calculated volumetric flow rate was compared with the actual flow rate, given by the numerical CFD simulations. With these values, the nozzle specific coefficient of discharge for several volumetric flow rates has been calculated and a function fitting was done to get obtain analytical relation between pressure and volumetric flow rate. The detailed design process of the three nozzles, the numerical results of the CFD studies and the determination of the nozzle specific coefficients of discharge are shown and discussed in detail in this work.

Determination of the Near-Wellbore Pressure Drop for Dual Casing in Hydraulic Fracturing and Refracturing Applications

2022 ◽  
Author(s):  
Joern Loehken ◽  
Davood Yosefnejad ◽  
Liam McNelis ◽  
Bernd Fricke
Keyword(s):  
Pressure Drop ◽  
Hydraulic Fracturing ◽  
Complex Flow ◽  
Cement Layer ◽  
Natural Rock ◽  
Wellbore Pressure ◽  
Flow Through ◽  
The Difference ◽  
Coefficient Of Discharge

Abstract Due to the increases in completion costs demand for production improvements, fracturing through double casing in upper reservoirs for mature wells and refracturing early stimulated wells to change the completion design, has become more and more popular. One of the most common technologies used to re-stimulate previously fracked wells, is to run a second, smaller casing or tubular inside of the existing and already perforated pipes of the completed well. The new inner and old outer casing are isolated from each other by a cement layer, which prevents any hydraulic communication between the pre-existing and new perforations, as well as between adjacent new perforations. For these smaller inner casing diameters, specially tailored and designed re-fracturing perforation systems are deployed, which can shoot casing entrance holes of very similar size through both casings, nearly independent of the phasing and still capable of creating tunnels reaching beyond the cement layer into the natural rock formation. Although discussing on the API RP-19B section VII test format has recently been initiated and many companies have started to test multiple casing scenarios and charge performance, not much is known about the complex flow through two radially aligned holes in dual casings. In the paper we will look in detail at the parameters which influence the flow, especially the Coefficient of Discharge of such a dual casing setup. We will evaluate how much the near wellbore pressure drop is affected by the hole's sizes in the first and second casing, respectively the difference between them and investigate how the cement layer is influenced by turbulences, which might build up in the annulus. The results will enhance the design and provide a better understanding of fracturing or refracturing through double casings for hydraulic fracturing specialists and both operation and services companies.

Experimental and Computational Investigation of Coefficient of Discharge of Venturimeter

2021 ◽  
pp. 57-72
Author(s):  
Omprakash Yadav ◽  
Abhay Dahiya ◽  
Vinod Kumar Yadav ◽  
Rahul Sharma
Keyword(s):  
Computational Investigation ◽  
Coefficient Of Discharge
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