Water Flow Rate Measurements Research Articles

Adaptation of segmented elbow on the flow meter by using CFD tools

This paper presents the possibility of non-invasive adaptation of the existing pipeline infrastructure in front of the condenser to the measurement of cooling water flow rate. In the analyzed variant, for the measurement of water flow rate in the cooling system, local pressure difference in the segmented elbow was applied. CFD (ANSYS CFX) was used as a tool for diagnosing flow structure, including the location of sampling points of pressure in the elbow. Many variants of flow were modelled (“What if?” analysis type) in this paper. These variants were used to determine the correlation between the differential pressure in the elbow and the flow rate. In addition, the article identifies the advantages and disadvantages of the solutions of this type against a background of standard elements and measuring distances and discusses the basic procedures for preparing and conducting CFD numerical experiment.

Hydraulics of smoothly streamlined Venturi channels of critical depth

The article relates to the field of hydraulics and engineering hydrology and is devoted to a study of fluid flow in a non-flooded Venturi channel. The purpose of the work is improvement of methods for calculating profiles and hydraulic characteristics of a Venturi flumes used for measurement of water flow rates in open channels and rivers. Research methods are analytical with experimental verification. A functional relationship is obtained between the Froude number in an arbitrary section of the Venturi channel and its width normalized by the width of the critical section. It is established that within a rectilinear gorge portion of a Venturi channel, the flow is unstable, which is related to the proximity of its parameters to the critical ones. The method of optimization of a profile of a Venturi channel with a dividing cross-section in a gorge that does not contain empirical coefficients is considered. It is shown that the proposed method allows determining all main geometric parameters and hydraulic characteristics of the Venturi flume, including its flow rate coefficient, distribution of depths and flow velocities along the length of a flume with a relative error of ±1%.

Water absorption into stems affects the measurement of vulnerability curves as a function of plant water status

Xylem hydraulic properties are of great significance for plant growth and performance under drought. The ability of plants to avoid drought-induced cavitation and loss of hydraulic conductivity (K) can be characterized with vulnerability curves (VC). A VC describes the sigmoidal relationship between percentage loss of K (PLC) and xylem water potential (ψxyl). The ψ at 50% loss of conductance indicates a commonly used threshold for detrimental embolism (P50). The slope (b) represents cavitation resistance. The standard hydraulic method to determine VC's requires the measurement of water flow rate (WFR) per pressure gradient through stem segments, either by measuring outflow from the stem gravimetrically or inflow using a flow meter. In a comparative study using both measurements of inflow and outflow in asparagus stems, we found considerable disparities in the resulting shapes of VCs (P50 and b). We hypothesized that water uptake of stem tissue occurs during the pressure-driven water transit, particularly at low water potential and that differences in the initial K might result from measurements of inflow or outflow. To determine whether water uptake of stem tissue occurs during K measurements of asparagus plants, we tested for effects of ψxyl on the initial inflow and outflow K at different pressure gradients and investigated if passive water uptake can be estimated by extrapolation from the linear regression between WFR and pressure gradient based on K at two pressures. Initial K differed significantly between inlet and outlet measurements at low ψxyl, whereas maximum K did not, providing evidence of water uptake during transit through droughted stems. The resulting parameters P50 and b, and thus the shape of VCs, differed as well. The extrapolation resulted in the first estimate of passive water uptake, leading to a convergence of the VC at inlet and at outlet. We conclude that differences between in- and outflow may play a major role in K measurements.

Non-invasive estimation of domestic hot water usage with temperature and vibration sensors

Electric water heaters are responsible for a large portion of electricity consumption and water usage in the domestic sector. Smart water heaters alleviate the strain on the electricity supply grid and reduce water consumption through behavioural change, but the installation of in-line flow meters is inconvenient and expensive. A non-invasive water flow meter is proposed as an alternative. Non-invasive flow measurement is more common for high flow rates in the industrial sector than for domestic applications. Various non-invasive water measurement methods are investigated in the context of domestic hot water, and a combination of thermal- and vibration-sensing is proposed. The proposed solution uses inexpensive, easily installable, non-invasive sensors and a novel algorithm to provide the same flow measurement accuracy as existing in-line meters. The algorithm detects the beginning and end of water consumption events with an accuracy of 95.6%. Quantitative flow rate estimation was possible for flow rates greater than 5 L min−1 with an accuracy of 89%, while volumetric usage estimation had an accuracy of more than 93%. The algorithm limitations were applied to field data, revealing that water consumption could be detected with an error of less than 12% within the limitations of the proposed algorithm. The paper presents a successful proof of concept for a non-invasive alternative to domestic hot water flow rate measurement.

Design and development of a novel water flow measurement system

Abstract The present paper reports the design and developmental aspects of a prototype of an automatic primary water flow standard. The system is based on a unique technique of carrying out multiple weighing using double weighing tanks. The multiple weighing technique has advantages of increasing the collection time by collecting large water mass thereby reducing the diverter error, the main source of measurement uncertainty, consequently improving measurement uncertainty of the system. The longer collection time minimizes the effect of diverter error. This makes cumbersome process of diverter error evaluation insignificant and may be avoided. Another advantage is to use either of the two tanks in case of any one of the tanks becomes out of order and using another tank as stand alone in a single weighing compromising bit measurement uncertainty. The system thus developed is capable of measuring water flow rate and/calibrating different water flow meters having size (15–100) mm, in the flow range from 0.3 m 3 /h to 100 m 3 /h. The estimated relative expanded uncertainties of the system for collected water mass of 2000 kg, 1500 kg, 1000 kg and 500 kg are found as 0.055%, 0.056%, 0.061% and 0.081% (at k = 2), respectively which is sufficient for industrial dissemination. The present designed and developed prototype system is a low-cost solution to users and industries which is easier to operate and maintain with comparable existing systems.

Vapour discharges on Nevado del Ruiz during the recent activity: Clues on the composition of the deep hydrothermal system and its effects on thermal springs

The Nevado del Ruiz volcano is considered one of the most active volcanoes in Colombia, which can potentially threaten approximately 600,000 inhabitants. The existence of a glacier and several streams channelling in some main rivers, flowing downslope, increases the risk for the population living on the flank of the volcano in case of unrest, because of the generation of lahars and mudflows. Indeed, during the November 1985 subplinian eruption, a lahar generated by the sudden melting of the glacier killed twenty thousand people in the town of Armero. Moreover, the involvement of the local hydrothermal system has produced in the past phreatic and phreatomagmatic activity, as occurred in 1989. Therefore, the physico-chemical conditions of the hydrothermal system as well as its contribution to the shallow thermal groundwater and freshwater in terms of enthalpy and chemicals require a close monitoring. The phase of unrest occurred since 2010 and culminated with an eruption in 2012, after several years of relative stability, still maintains a moderate alert, as required by the high seismicity and SO2 degassing.In October 2013, a sampling campaign has been performed on thermal springs and stream water, located at 2600–5000m of elevation on the slope of Nevado del Ruiz, analyzed for water chemistry and stable isotopes. Some of these waters are typically steam-heated (low pH and high sulfate content) by the vapour probably separating from a zoned hydrothermal system. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of hydrothermal steam discharging in the different springs. The composition of the hottest thermal spring (Botero Londono) is probably representative of a marginal part of the hydrothermal system, having a temperature of 250°C and low salinity (Cl ~1500mg/l), which suggest, along with the retrieved isotope composition, a chiefly meteoric origin.The vapour discharged at the steam vent “Nereidas” (3600masl) is hypothesized to be separated from a high-temperature hydrothermal system. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep hydrothermal system, as well as its pH and fO2. The vapour feeding Nereidas would separate from a biphasic hydrothermal system characterized by the following parameters:t=315°C, P=15MPa, NaCl=10wt%, CO2=5wt%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, pH would approach the value of 1.5 while fO2 would correspond to the FeO-Fe2O3 buffer. Chlorine content is estimated at 10,300mg/l. Changes in the magmatic input into the hydrothermal system could modify its degree of vapourization and/or P-T-X conditions, thus inducing corresponding variations in vapour discharges and thermal waters. These findings, paralleled by contemporary measurements of water flow rates, could give significant clues on risk evaluation.

NON-INTRUSIVE METHOD FOR MEASURING WATER FLOW RATE IN PIPE

The transducer most widely used for vibration measurement is the piezoelectric accelerometer. This application has been explored for flow rate measurement, since some studies have verified the narrow correlation between ratio of flow and vibration. The technique consists of measure the vibration induced by the flow in the pipeline, has been considered as promising, in the sense of enabling the development of a sensor that presents advantageous characteristics such as non-intrusiveness, non-invasiveness and reduced cost. This paper shows the method of measurement of flow in pipe based on vibration caused by transit of water, without the need of flow interruption or opening of pipe for installation of water meters. Further are present experimental measurements and metrological validation in laboratory accredited for calibration of flow meters.

Finite element modelling of permeability in brittle materials cracked in tension

Cracking in structures significantly affects their durability, water transfer and ultimately their safety. This structural disorder provides a preferential path for the penetration of fluids and contributes significantly to the deterioration of the material.In this work, a macroscopic model intended to predict the change of permeability with respect to cracking is proposed. The development reported here is implemented within an orthotropic continuum damage model able to calculate crack openings. The proposed model assumes an initially isotropic permeability tensor, which becomes anisotropic with damage. The objectivity of the hydraulic response toward the finite element mesh is ensured by considering the crack localization problem when building the permeability tensor. Finally, the model is used to simulate cracking and permeability variations on virtual and real structures. The simulation results are compared with experimental water flow rate measurements through a real reinforced concrete element subjected to tensile loading as found in the literature.

Impact of Pitot tube calibration on the uncertainty of water flow rate measurement

Water utility companies often use Cole type Pitot tubes to map velocity profiles and thus measure flow rate. Frequent monitoring and measurement of flow rate is an important step in identifying leaks and other types of losses. In Brazil losses as high as 42% are common and in some places even higher values are found. When using Cole type Pitot tubes to measure the flow rate, the uncertainty of the calibration coefficient (Cd) is a major component of the overall flow rate measurement uncertainty. A common practice is to employ the usual value Cd = 0.869, in use since Cole proposed his Pitot tube in 1896. Analysis of 414 calibrations of Cole type Pitot tubes show that Cd varies considerably and values as high 0.020 for the expanded uncertainty are common. Combined with other uncertainty sources, the overall velocity measurement uncertainty is 0.02, increasing flowrate measurement uncertainty by 1.5% which, for the Sao Paulo metropolitan area (Brazil) corresponds to 3.5 × 107 m3/year.

Measurement of vertical oil-in-water two-phase flow using dual-modality ERT–EMF system

Oil-in-water two-phase flows are often encountered in the upstream petroleum industry. The measurement of phase flow rates is of particular importance for managing oil production and water disposal and/or water reinjection. The complexity of oil-in-water flow structures creates a challenge to flow measurement. This paper proposes a new method of two-phase flow metering, which is based on the use of dual-modality system and multidimensional data fusion. The Electrical Resistance Tomography system (ERT) is used in combination with a commercial off-the-shelf Electromagnetic Flow meter (EMF) to measure the volumetric flow rate of each constituent phase. The water flow rate is determined from the EMF with an input of the mean oil-fraction measured by the ERT. The dispersed oil-phase flow rate is determined from the mean oil-fraction and the mean oil velocity measured by the ERT cross-correlation velocity profiling. Experiments were carried out on a vertical upward oil-in-water pipe flow, 50mm inner-diameter test section, at different total liquid flow rates covering the range of 8–16m3/hr. The oil and water flow rate measurements obtained from the ERT and the EMF are compared to their respective references. The accuracy of these measurements is discussed and the capability of the measurement system is assessed.

Low-power micro-fabricated liquid flow-rate sensor

We have constructed micro-fabricated flow sensors that can measure water flow rates of 0.1 to 2.0 gallons per minute (GPM), and the experimental results we obtained are in good agreement with those from COMSOL simulations.

Development of rectangular broad-crested weirs for flow characteristics and discharge measurement

One of the important problems which designers and engineers are faced with is proper measurement of water flow rates in open channels and rivers. To solve this problem, the water discharge to be precisely measured in water conveyance systems such as off takes and distribution ditches. The common procedure to meet this requirement is achieved by using water-measuring structures such as flumes, orifices, weirs and current meters. Among the mentioned structure, engineers prefers the weirs because of their simple structure and economical features. The broad-crested rectangular weirs are very common which are widely used in water ways and canals. In this study, the effect of steeping in the upstream side of rectangular broad-crested weirs over discharge coefficient and flow characteristics is investigated. Five weirs with 15, 30, 45, 60 and 90 weir angles were developed and flow discharge coefficient, negative velocity over the weir crest edge and water surface profiles along the weir crest evaluated in laboratory hydraulic flume. The obtained results showed by decreasing the slope of the upstream side, discharge efficiency and the discharge capacity of the weir are increased subsequently. Consideration of experimental data it is obvious that by using the proposed weir with slope of 15 degree in comparison with standard weir, the efficiency is increased up to 19.17%. It is noteworthy that by reducing the slope, return current on the crest is not observed.

Thermal-wave balancing flow sensor with low-drift power feedback

A control system using a low-drift power-feedback signal was implemented applying thermal waves, giving a sensor output independent of resistance drift and thermo-electric offset voltages on interface wires. Kelvin-contact sensing and power control is used on heater resistors, thereby inhibiting the influence of heater resistance drift. The thermal waves are detected with a sensing resistor using a lock-in amplifier and are mutually cancel­led by a thermal-wave balancing controller. Offset due to thermal gradient across the chip and resistor drift are eliminated by the lock-in amplifier and power controller, and therefore do not influence the sensor output signal. A microchannel thermal-wave balancing flow sensor with integrated Al resistors has successfully been fabricated. The thermal flow sensor is capable of measuring water flow rates with nl ⋅ min−1 precision, up to about 500 nl ⋅ min−1 full scale. Measurement results are in good agreement with a dynamic model of the flow sensor. Drift measurements show the sensor output signal to be compensated for resistance drift and thermal gradient across the chip.

Uncomplicated Setting Apparatus for Measurement of Fluid Flow Rate Using Laser Doppler Technique: Physics Teaching

Laser Doppler velocimetry (LDV) or laser Doppler anemometry (LDA) is the technique of using the Doppler shift in a laser beam to determine the fluid velocity. In this work, dual beam mode (two incident beams, single observation location) was selected to use. A cost effective and easy module for measurement of water flow rate was designed and constructed. A He-Ne laser with a wavelength of 632.8 nm was used as a light source. The laser was passed through a beam splitter and divided into two beams with identical intensity and coherence. Subsequently, the two laser beams travelled to a focusing lens with a focal length of 100 mm and focused on a center of water flow channel in quartz cuvette with a dimension of 1 × 1 × 5 cm3. The beam angle was set at 4.96°. When the seeding particles, bubbles and microorganism in water, were moving through the intersection point of two beams, the light was scattered. The scattered light was collected by photodetector connected to processing system. The frequency of scatterred light is shifted according to the Doppler shift relations due to effect of Rayleigh scattering. The water flow rate can be calculated from Doppler shift frequency.

An electrode polarization impedance based flow sensor for low water flow measurement

This note describes an electrode polarization impedance based flow sensor for low water flow measurement. It consists of two pairs of stainless steel electrodes set apart and inserted into a non-conductive flow tube with each pair of electrodes placed diametrically at the opposite sides. The flow sensor is modeled as a typical four-electrode system of which two electrodes are current-carrying and the other two serve as output pick ups. The polarization impedances of the two current carrying electrodes are affected by water flows resulting in changes of differential potential between the two pick-up electrodes which are separated by the same fluid. The interrogation of the two excitation electrodes with dc biased ac signals offers significantly higher sensor sensitivities to flow. The prototype flow sensor constructed for a 20 mm diameter pipeline was able to measure water flow rate as low as tested at 1.06 l h−1 and remained sensitive at a flow rate of 25.18 l h−1 when it was driven with a sinusoidal voltage at 1000 Hz with a peak ac amplitude of 2 V and a dc offset of +8 V. The nonlinear characteristics of the sensor response indicate that the sensor is more sensitive at low flows and will not be able to measure at very high flows. Additional experiments are needed to evaluate the influences of impurities, chemical species, ions constituents, conductivity and temperature over a practical range of residential water conditions, the effects of fluctuating ground signals, measurement uncertainty, power consumption, compensation of effects and practical operations. The flow sensor (principle) presented may be used as (in) a secondary sensor in combination with an existing electronic water meter to extend the low end of measurement range in residential water metering.

Hormone loads exported by a tile-drained agroecosystem receiving animal wastes

Little is known regarding hormone export from tile-drained agricultural fields despite the widespread presence of tile drains in the Midwestern United States. By intensively measuring water flow rates and hormone concentrations in four subsurface tile drains and three receiving ditches at a working Midwest farm, hormone fluxes and loads from the tile-drained fields were quantified. Before and during the 17-month study period (January 2009 – May 2010), the associated farm fields received various animal waste applications (beef, dairy, poultry, sheep, and swine). Hormones monitored included the estrogens17β- and 17α-estradiol, estrone, and estriol; the natural androgens testosterone, and androstenedione; and the synthetic androgens 17β- and 17α-trenbolone, and trendione. Hormone loads measured in the ditches for three drainage areas during the entire 17-month study period were in ranges of 16–58 mg/ha for total estrogens, 6.8–19 mg/ha for natural androgens, and 4.2–44 mg/ha for synthetic androgens. Because higher hormone concentrations generally occurred during discrete periods of increased flow, high flow rates often were associated with a disproportionately high hormone flux. For example, 80% of total estrogens and natural androgens exported into the ditches occurred during only 9–26% of the study period, coinciding with the most significant storm events. In addition, hormone fluxes were highest during storm events that occurred shortly after animal waste applications. Therefore, to effectively reduce hormone loads exported to downstream aquatic ecosystems in the absence of any application reduction, the short periods during which high-flow events occur must be targeted. Copyright © 2012 John Wiley & Sons, Ltd.

Mining Linguistic Associations for Emergent Flood Prediction Adjustment

Floods belong to the most hazardous natural disasters and their disaster management heavily relies on precise forecasts. These forecasts are provided by physical models based on differential equations. However, these models do depend on unreliable inputs such as measurements or parameter estimations which causes undesirable inaccuracies. Thus, an appropriate data-mining analysis of the physical model and its precision based on features that determine distinct situations seems to be helpful in adjusting the physical model. An application of fuzzy GUHA method in flood peak prediction is presented. Measured water flow rate data from a system for flood predictions were used in order to mine fuzzy association rules expressed in natural language. The provided data was firstly extended by a generation of artificial variables (features). The resulting variables were later on translated into fuzzy GUHA tables with help of Evaluative Linguistic Expressions in order to mine associations. The found associations were interpreted as fuzzy IF-THEN rules and used jointly with the Perception-based Logical Deduction inference method to predict expected time shift of flow rate peaks forecasted by the given physical model. Results obtained from this adjusted model were statistically evaluated and the improvement in the forecasting accuracy was confirmed.

Parametric excitation of a micro Coriolis mass flow sensor

We demonstrate that a micro Coriolis mass flow sensor can be excited in its torsional movement by applying parametric excitation. Using AC-bias voltages for periodic electrostatic spring softening, the flow-filled tube exhibits a steady vibration at suitable voltage settings. Measurements show that the sensor for this type of excitation can be used to measure water flow rates within a range of 0 ± 500 μl/h with an accuracy of 1% full scale error.

PENGARUH TEKANAN PISTON PADA PENGATURAN KATUP SOLENOID PROPORSIONAL DUA ARAH TERHADAP LAJU ALIRAN AIR PADA SISTEM KALIBRASI PISTON PROVER OT-400

In order to use piston prover OT-400 calibrator more effective is to know the relationship between pressure piston and water flow rate. Water flow rate measurement by using piston pressure variation and setting of proportional directional solenoid valve has been done on piston prover OT-400 calibration sytems. Selection variation of piston pressure condition has been done at four measuring points there are 20 PSI, 42.5 PSI, 62.5 PSI and 80 PSI. Giving of voltage variation for ascending and declining to the solenoid is to set the opening and closing its valve. From the measurement results obtained that the water flow rate is proportional to the piston pressure used. Graph of water flow rate (Q) with unit of liters / minute versus the piston pressure (P) with unit of PSI within the setting ofproportional directional solenoid valve on the piston prover OT-400 calibrator has linear type that is Q = 0.002. P + 0.151 with R2=0,998. While the graph of the average uncertainty value of the measuring point versus pressure piston is not a linear form with the smallest value of 2.31% on the use of piston pressure of 80 PSI

Contribution of the Steady State Method to Water Permeability Measurement in Very Low Permeability Porous Media

Very low permeability geomaterials (order of nanoDarcy (10-21 m2 )), such as clay rocks, are of interest for many industrial applications including production from unconventional reserves of oil and gas, CO2 geological storage and deep geological disposal of high-level long-lived radioactive waste. In these last two applications, the efficiency of clay, as a barrier, relies on their very low permeability. Yet, laboratory measurement of low permeability to water (below 100 nD (10-19 m2 )) remains a technical challenge. Some authors (Hsieh et al. , 1981, Int. J. Rock Mech. Min. Sci. Geomech. Abstr. 18 , 245-252) argue that steady state methods are irrelevant due to the time required to stabilize water fluxes in such low permeability media and prefer a transient technique called pulse decay. This study aims to perform and compare transient and steady state techniques on three samples. Regarding the steady state method, a high precision pump was used to measure water flow rate through the sample. We show that with a suitable set-up, the steady state method enables us to measure a very low permeability of 0.8 nD (8 × 10-22 m2 ) over a period of three days and 2.6 nD (2.6 × 10-21 m2 ) over a period of one day. While the pulse decay test provides only an average estimate of the permeability for a comparable duration. Many issues are raised in pulse decay tests: determination of the reservoirs storage factor, micro leakage effects, determination of the initial pulse pressure, 2D mechanical effect. Contrary to the widespread belief that transient techniques are required to measure very low permeability, we show that direct steady state measurement of water permeability, with suitable equipments, can be much faster and more accurate than measurement by pulse decay. In fact, low water and rock compressibilities result in fast propagation of pressure wave and it cannot be argued that steady state conditions are not reachable in a reasonable amount of time. Still, pulse decay remains an interesting alternative to steady state methods when permeability is higher than 50 nD (5 × 10-20 m2 ).