scholarly journals ON ISSUE OF CALCULATION AND USE OF PARSHALL FLOW-METERING FLUME WITH MODERN WATER METERING DEVICES

2020 ◽  
Author(s):  
L. V. Yuchenko ◽  
◽  
A. P. Vasilchenko ◽  
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Measured Parameter ◽  
Measuring Device ◽  
Flow Metering ◽  
Measured Water ◽  
Water Metering

Purpose: the use of a flow-metering flume and a modern metering device for water metering in an open canal with a flow rate of up to 1.5 cubic meters per second with the subsequent prospect of automating the measurement process. Materials and methods: the main function of the hydrometric structure – giving the fluid flow a given regime and pattern within a limited channel is theoretically used in the article. With the help of a hydrometric structure (Parshall flume) using the well-known “velocity-area” method, it is possible to determine the functional dependence of the water flow rate on one measured parameter, in this case on the level. With the use of modern sensors or devices for metering this parameter, it is easy in the future to automate the process of its metering, registration and transmission over a distance. Results and Discussion: the calculation of the maximum flow rate of the chute according to the selected empirical formula showed the correct selection and calculation of its parameters for the structure in accordance with a given maximum flow rate (up to 1.5 cubic meters per second), which does not require additional calibration of the chute during application. Conclusions: recently, more and more attention has been paid to the accuracy of used water metering in open irrigation canals with a low flow rate. With introduction of new modern devices that convert the measured parameter into the amount of measured water flow, the relevance of their use together with hydrometric devices increases. To measure water flow in an open canal, it is proposed to use Parshall flume with a modern measuring device, consisting of a submersible pressure sensor and a remote control and monitoring unit installed in a stilling well. The description of design and an example of clarifying the geometric dimensions of a flume with a measured water flow rate of up to 1.5 cubic meters per second is provided. The design diagrams of the flume and stilling well with the placement of a modern measuring device are presented.

scholarly journals Methodology of calculation the maximum flow rate of suspended sediments of mudflows (within Nakhchivan Autonomous Republic)

2019 ◽  
pp. 98-104
Author(s):  
J. H. Mammadov
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Catchment Area ◽  
Forest Cover ◽  
Water Flow Rate ◽  
Maximum Flow ◽  
Suspended Sediments ◽  
Maximum Flow Rate ◽  
Natural Factors ◽  
Maximum Water

The main natural factors that have a significant impact on the maximum flow rate of suspended sediments are identified. The most universal of these factors is the maximum water flow rate, which creates an opportunity for the formation and development of mudflow processes, as well as determines the power of the mudflow. As a rule, the maximum flow rate of suspended sediments increases with increasing catchment area. At the same time, the larger the size of a river basin is, the greater the impact of various physical and geographical factors. Such complex factors include: Qmax – the maximum water flow rate, φ – the coefficient of natural over regulation of rivers, ϒ – the index of ploughness, Ψ – the forest cover index, İ – the slope of the catchment area. These factors are closely interrelated and interdependent, as mudflows are, to a certain extent, a mirror reflecting the influence of the main natural and anthropogenic factors. It seems to us that of the above factors determining the general background, the most universal ones are singled out for calculating the maximum flow rate of suspended sediments. We believe that there should also be a link between the values of the maximum flow rate of suspended sediments and the set of parameters that more clearly reflect the influence of natural factors. In this regard, in individual basins of any territory mudflows appear with different capacity. The relationships between the maximum flow rate of suspended sediments and the complex of natural factors reflect hydrological and geological-geomorphological conditions. Horizontal and vertical differentiation of mountain slopes with different exposures allowed us to identify this dependence in the form of 3 equations. The first two equations characterize the increase of maximum flow of suspended sediments in watershed and plowed slopes that lead to the maximum flow rate of suspended sediments. But forest cover and the coefficient of rivers flood natural overregulation lead to the lowest flow rate of suspended sediments. The third equation is characterized by the largest increase in water flow rate and in the average height of the catchment, which increases the maximum flow rate of suspended sediments, and the catchment area and the natural over regulation of rivers leads to its reduce.

scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

Lichen sclerosis–induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft

2021 ◽  
pp. 039156032110033
Author(s):  
Atef Fathi ◽  
Omar Mohamed ◽  
Osama Mahmoud ◽  
Gamal A Alsagheer ◽  
Ahmed M Reyad ◽  
...  
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Urine Volume ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
P Value ◽  
Onlay Graft ◽  
Voiding Symptoms ◽  
Stricture Recurrence

Background: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). Methods: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. Results: Thirty patients were identified. The median age (range) was 39 (25–61) years and a median (range) stricture length was 8 (6–14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12–24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2–11) ml/s preoperatively to 18 (range: 6–23) ml/s at the 6th month ( p value < 0.001). Conclusion: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

Experimental Characterization of a Modified Airlift Pump

2014 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Keegan Fernandes
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
High Speed ◽  
Water Flow Rate ◽  
High Speed Photography ◽  
Two Phase ◽  
Inner Diameter ◽  
Airlift Pump ◽  
Flow Map ◽  
Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

scholarly journals Impacts of Water Flow Rate on Freezing Prevention of Air-Cooled Heat Exchangers in Power Plants

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 112 ◽  
Author(s):  
Yonghong Guo ◽  
Huimin Wei ◽  
Xiaoru Yang ◽  
Weijia Wang ◽  
Xiaoze Du ◽  
...  
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Power Plants ◽  
Water Flow Rate

scholarly journals Maximum Flow Rate of a Single Component, Two-Phase Mixture

1965 ◽  
Vol 87 (1) ◽  
pp. 134-141 ◽  
Author(s):  
F. J. Moody
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Maximum Flow ◽  
Single Component ◽  
Maximum Flow Rate ◽  
Vapor Flow ◽  
Two Phase ◽  
Slip Ratio ◽  
Phase Mixture ◽  
Local Slip

A theoretical model is developed for predicting the maximum flow rate of a single component, two-phase mixture. It is based upon annular flow, uniform linear velocities of each phase, and equilibrium between liquid and vapor. Flow rate is maximized with respect to local slip ratio and static pressure for known stagnation conditions. Graphs are presented giving maximum steam/water flow rates for: local static pressures between 25 and 3,000 psia, with local qualities from 0.01 to 1.00; local stagnation pressures and enthalpies which cover the range of saturation states.

Effect of Blade Angle of Attack and Hub to Tip Ratio on Mass Flow Rate in an Axial Fan at a Fixed Rotational Speed

2008 ◽  
Author(s):  
Mohammad J. Izadi ◽  
Alireza Falahat
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Angle Of Attack ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Maximum Mass ◽  
Blade Angle ◽  
Axial Fan

In this investigation an attempt is made to find the best hub to tip ratio, the maximum number of blades, and the best angle of attack of an axial fan with flat blades at a fixed rotational speed for a maximum mass flow rate in a steady and turbulent conditions. In this study the blade angles are varied from 30 to 70 degrees, the hub to tip ratio is varied from 0.2 to 0.4 and the number of blades are varied from 2 to 6 at a fixed hub rotational speed. The results show that, the maximum flow rate is achieved at a blade angle of attack of about 45 degrees for when the number of blades is set equal to 4 at most rotational velocities. The numerical results show that as the hub to tip ratio is decreased, the mass flow rate is increased. For a hub to tip ratio of 0.2, and an angle of attack around 45 degrees with 4 blades, a maximum mass flow rate is achieved.

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