scholarly journals Accuracy and Reliability Analysis of Pipe Irrigation Metering Device for Sandy Water Source

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 947
Author(s):  
Mingxiao Su ◽  
Xiyun Jiao ◽  
Jiang Li ◽  
Shuyu Wu ◽  
Tianao Wu
Keyword(s):  
Flow Velocity ◽  
Relative Error ◽  
Flow Rate ◽  
Electromagnetic Flowmeter ◽  
Sediment Concentration ◽  
Ultrasonic Flowmeter ◽  
Muddy Water ◽  
Relative Errors ◽  
The Right ◽  
Water Meter

Sandy water sources are widely distributed and are important for agricultural development. However, no explicit result has been achieved in the research of the accuracy and reliability of pipeline metering devices as well as flow rate measurement objects (water or water–sand) of different metering devices in the process of pipelines conveying muddy water. In this study, seven kinds of sediment concentration gradients, C0–C6 (0.2–7.19%), and three different flow velocities (1.0 m/s, 1.25 m/s, 1.5 m/s) were set up, and a comparison measuring method was used to compare the flow values of three kinds of metering device (electromagnetic flowmeter, ultrasonic flowmeter and water meter) with a right triangle weir. The accuracy and reliability of the metering device were obtained by analyzing the change law of the relative error between each metering device and the right triangle weir under different flow velocities and different sediment concentrations, and the flow rate measurement objects of each metering device were finally clarified. The relative error between the electromagnetic flowmeter and right triangle weir decreased gradually with the increase in the flow velocity when the sediment concentration was constant. The maximum difference of the relative error between the electromagnetic flowmeter and the right triangle weir was 2.53% when the flow velocity was constant. Additionally, the minimum differences of the relative errors of the ultrasonic flowmeter and water meter were 2.67% and 6.90%, respectively. The measured flow law of the electromagnetic flowmeter was more in line with the measured flow law of the water–sand mixture measured by the right triangle weir. However, the relative errors of water and water–sand measured by the ultrasonic flowmeter and water meter fluctuate greatly, which does not accord with the law of muddy water measured by the right triangle weir. The results showed that the electromagnetic flowmeter has the best reliability among the three metering devices, and the accuracy can be improved by calibration before use or increasing the flow velocity of the pipe network. Under the sand grading used in this study, the electromagnetic flowmeter was recommended to measure the flow rate of pipe irrigation for sandy water sources in this paper.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

On-Line Monitoring System for Monitoring SO2 in Fumes (1) — Monitoring Subsystem for SO2 Mass Concentration

2011 ◽  
Vol 422 ◽  
pp. 296-299
Author(s):  
Shi Long Wang ◽  
Li Na Wang ◽  
Hong Bo Wang ◽  
Yong Hui Cai
Keyword(s):  
Flow Velocity ◽  
Monitoring System ◽  
Flow Rate ◽  
Mass Concentration ◽  
National Monitoring ◽  
Monitoring Result ◽  
Short Period ◽  
On Line ◽  
Working Principle

In order to achieve the target of controlling SO2 emissions in fumes in a short period of time in China, a SO2 on-line monitoring system (CEMS) has been developed by the authorased on the principle of electrochemistry. This system consists of two subsystems: (1) SO2 mass concentration monitoring and (2) SO2 flow velocity and flow rate monitoring. In the paper, the procedure of system and working principle and method of SO2 mass concentration monitoring subsystem are described in detail (SO2 flow velocity and flow rate monitoring subsystem is described by another paper).Two subsystems work synchronously to monitor and calculate the SO2 emissions, then the on-line monitoring of SO2 emissions is achieved. Through experiment and testing, monitoring result of the system is stable and reliable, which has reached the national monitoring standards and passed the appraisal.

scholarly journals The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangzhengyuan Yuan ◽  
Chuan Liu ◽  
Shiyong Yu ◽  
Shizhu Bian ◽  
Jie Yang ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Flow Velocity ◽  
Healthy Subjects ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Tricuspid Annulus ◽  
Doppler Flow ◽  
The Right ◽  
Rv Function

IntroductionPulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear.MethodsA total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e’. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO.ResultsAfter HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (−)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s’) at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (−) group. Additionally, increased tricuspid ICV and mitral/tricuspid s’ were found only in the notch (−) group.ConclusionHA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s’, reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.

scholarly journals RESEARCH AND APPLICATION OF METHODS FOR CALCULATING THE MEASUREMENT UNCERTAINTY OF INDUSTRIAL FLOWMETERS

2020 ◽  
Vol 6 (444) ◽  
pp. 145-153
Author(s):  
S. G. Khan ◽  
◽  
L. K. Ibrayeva ◽  
N. V. Syabina ◽  
Z. M. Yuldashev ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Measurement Uncertainty ◽  
Relative Error ◽  
Electromagnetic Flowmeter ◽  
Standard Uncertainty ◽  
Practical Application ◽  
Labview Software ◽  
Complex Measurement ◽  
Measurement Equations ◽  
Mobile Complex

To create conditions for the recognition of Kazakhstani certificates of conformity and the results of product tests, an assessment of measurement uncertainty is required. In this regard, there has been an increase in the practical application in Kazakhstan of the concept of measurement uncertainty. The authors developed a physical stand for a mobile complex designed to verify electromagnetic flowmeters at the place of operation. To obtain verification results, programs were developed to calculate the uncertainty of an electromagnetic flowmeters using the NI LabView software. In addition, a model for estimating the uncertainty of the relative error of flowmeters was proposed, and the measurement uncertainty was estimated using three methods: standard, Monte Carlo and Kragten. Finally, a comparative analysis was conducted on the results of the estimation of the uncertainty of the relative error of the industrial electromagnetic flowmeter. All methods give standard uncertainty values that do not exceed the acceptable range of relative error (± 1%). However, Monte Carlo method gives better results for sufficiently large number of simulations. No significant differences between the results obtained using standard and Kragten methods were discovered. The Kragten method is preferable in the absence of the need to calculate the sensitivity coefficients when calculating the total standard uncertainty, which is important for complex measurement equations.

Disequilibrium 1: Potential Gradients and Flows

1993 ◽  
Author(s):  
Brian Bayly
Keyword(s):  
Fresh Water ◽  
Flow Rate ◽  
Real Life ◽  
Water Levels ◽  
Bulk Flow ◽  
The Other ◽  
Water Salt ◽  
Potential Gradients ◽  
The Right ◽  
Two Sides

As in Chapter 2, so again here the intention is to review ideas that are already familiar, rather than to introduce the unfamiliar; to build a springboard, but not yet to leap off into space. The familiar idea is of flow down a gradient—water running downhill. Parallels are electric current in a wire, salt diffusing inland from the sea, heat flowing from the fevered brow into the cool windowpane, and helium diffusing through the membrane of a helium balloon. For any of these, we can imagine a linear relation: . . . Flow rate across a unit area = (conductivity) x (driving gradient) . . . where the conductivity retains a constant value, and if the other two quantities change, they do so in a strictly proportional way. Real life is not always so simple, but this relation serves to introduce the right quantities, some suitable units and some orders of magnitude. For present purposes, the second and fourth of the examples listed are the most relevant. To make comparison easier we imagine a barrier through which salt can diffuse and through which water can percolate, but we imagine circumstances such that only one process occurs at a time. Specifically, imagine a lagoon separated from the ocean by a manmade dike of gravel and sand 4 m thick, as in Figure 3.1. If the lagoon is full of seawater but the water levels on the two sides of the dike are unequal, water will percolate through the dike, whereas if the levels are the same and the dike is saturated but the lagoon is fresh water, salt will diffuse through but there will be no bulk flow of water. (More correctly, because seawater and fresh water have different densities, and because of other complications, the condition of no net water flow would be achieved in circumstances a little different from what was just stated. For present purposes all we need is the idea that conditions exist where water does not percolate but salt does diffuse.) For flow of water driven by a pressure gradient, suitable units are shown in the upper part of Table 3.1 and for diffusion of salt driven by a concentration gradient, suitable units are shown in the lower part.

Pushmi-Pullyu and the Right Atrium

2011 ◽  
pp. 55-62
Author(s):  
James R. Munis
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Right Ventricle ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
The Other ◽  
Right Atrial ◽  
The One ◽  
The Right ◽  
Point Of Intersection

What does right atrial pressure (PRA) do to cardiac output (CO)? On the one hand, we've been taught that PRA represents preload for the right ventricle. That is, the higher the PRA, the greater the right ventricular output (and, therefore, CO). This is simply an application of Starling's law to the right side of the heart. On the other hand, we've been taught that PRA represents the downstream impedance to venous return (VR) from the periphery. That is, the higher the PRA, the lower the VR, and therefore, the lower the CO. The point of intersection between the 2 curves defines a unique blood flow rate, which is both CO and VR at the same time.

scholarly journals Vertical Distribution of Suspended Sediments above Dense Plants in Water Flow

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 12 ◽  
Author(s):  
Yanhong Li ◽  
Liquan Xie ◽  
Tsung-chow Su
Keyword(s):  
Vertical Distribution ◽  
Flow Velocity ◽  
Suspended Sediment ◽  
Plant Height ◽  
Water Flow ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Turbulent Momentum ◽  
Different Diameters ◽  
Plane Displacement

Plants in natural water flow can improve water quality by adhering and absorbing the fine suspended sediments. Dense plants usually form an additional permeable bottom boundary for the water flow over it. In the flow layer above dense plants, the flow velocity generally presents a zero-plane-displacement and roughness-height double modified semi-logarithmic profile. In addition, the second order shear turbulent moment (or the Reynolds stress) are different from that found in non-vegetated flow. As a result, the turbulent momentum diffusivity of flow and thus the diffusivity of sediment will shift, which will cause the vertical profile of suspended sediment and the corresponding Rouse formula deform. A set of physical experiments with three different diameters of fine suspended sediments was conducted in an indoor water flume. These experiments investigated a new distribution pattern of suspended sediment and the correspondingly deformed Rouse formula in the flow layer over the dense plants. Experimental results showed that above the dense plants, the shear turbulent momentum of flow presented a plant-height modified negative linear profile, which has been proposed by a previous study, and the vertical distribution of fine suspended sediments presented an equilibrium pattern. Based on the plant-modified profiles of flow velocity and the shear turbulent momentum a new zero-plane and plant-height double modified Rouse formula were analytically derived. This double-parameter modified Rouse formula agrees well with the measured profile of suspended sediment concentration experimentally observed in the present study. By adjusting the Prandtl–Schmidt number, i.e., the ratio of sediment diffusivity to flow diffusivity, the double-parameter modified Rouse formula can be applied to submerged dense plant occupied flow.

scholarly journals Performance investigation of a volute porous tongue of a turbocharger turbine

2020 ◽  
Vol 40 (1) ◽  
pp. 59-66
Author(s):  
Abderrahmane Chachoua ◽  
Mohamed Kamal Hamidou ◽  
Mohammed Hamel
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Recirculation Flow ◽  
Recirculating Flow ◽  
Show Evidence ◽  
The Right

The design for better performance of the spiral housing volute used commonly in radial and mixed inflow gas turbines is of prime importance as it affects the machine stage at both design and off design conditions. The tongue of the scroll divides the flow into two streams, and represents a severe source of disturbances, in terms of thermodynamic parameter uniformity, maximum kinetic energy, the right angle of attack to the rotor and minimum losses. Besides, the volute suffers an undesirable effect due to the recirculating mass flow rate in near bottom vicinity of the tongue. The present project is an attempt to design a tongue fitted with cylindrical holes traversing normal to the stream wise direction, where on account of the large pressure difference between the top and the bottom sides of the tongue will force the recirculating flow to go through the rotor inlet. This possibility with its limitations has not yet been explored. A numerical simulation is performed which might provide our suitable objectives. To achieve this goal the ANSYS code is used to build the geometry, generate the mesh, and to simulate the flow by solving numerically the averaged Navier Stokes equations. Apparently, the numerical results show evidence of favorable impact in using porous tongue. The realization of a contact between the main and recirculation flow by drilled holes on the tongue surface leads to a flow field uniformity, a reduction in the magnitude of the loss coefficient, and a 20 % reduction in the recirculating mass flow rate.

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