scholarly journals Beyond the flow rate: the importance of thermal range, flow intensity, and distribution for water-efficient showers

2019 ◽  
Vol 27 (5) ◽  
pp. 4640-4660
Author(s):  
Kemi Adeyeye ◽  
Kaiming She ◽  
Inês Meireles
Keyword(s):  
Flow Rate ◽  
Discharge Rate ◽  
Water Discharge ◽  
Laboratory Data ◽  
User Feedback ◽  
Physical Parameters ◽  
Thermal Range ◽  
Temperature Loss ◽  
Spray Distribution ◽  
Flow Intensity

AbstractStudies show that user behaviours have not necessarily changed, despite the prevalence of water-efficient products in the market. One reason is because the technical emphasis for delivering the water use efficiency of products has focused on reducing the flow rate. Therefore, this study was undertaken to examine the physical parameters that define the technical efficiency of showerheads against the experiential performance (and therefore the satisfaction with the showerheads). These parameters were measured in a controlled laboratory environment and the findings were triangulated against user feedback from in-home trials. Synergies between the laboratory data and user feedback were found. Notably, it was found that water spray intensity, distribution, and temperature loss all impact the quality of showering experience. These factors also influence shower duration—and thus the volume of water used in the shower. Significantly, these technical metrics affected the overall experiential performance of such products from the users’ perspective. Therefore, the design of water-efficient showerheads, in addition to delivering water discharge savings, should avoid poor spray distribution, intensity, and heat retention. The implications of the findings are that water efficiency labelling and product standards should extend beyond the emphasis on limiting the flow rates—typically to 9 l per min for showerheads. This study shows good merit for including the spray intensity (pressure), distribution, and degree of heat loss, in addition to the discharge rate, as part of the performance and efficiency considerations of showerheads.

scholarly journals Emitter Clogging and Hydraulic Performance of Drip System under Different Water Qualities and Placement Techniques

2021 ◽  
pp. 98-111
Author(s):  
Deepak Singh ◽  
Neelam Patel ◽  
Nisha Singh ◽  
KG Rosin ◽  
Devideen Yadav ◽  
...  
Keyword(s):  
Flow Rate ◽  
Agricultural Research ◽  
Discharge Rate ◽  
Water Discharge ◽  
Indian Agricultural Research Institute ◽  
Total Solid ◽  
Total Coliform ◽  
Operating Pressure ◽  
E Coli ◽  
Medium Risk

The present study was conducted at the Indian Agricultural Research Institute, New Delhi, India, to evaluate the effect of sand-disc filters, pressure compensating (bioline) and non-pressure compensating (inline) emitters, and surface and subsurface placement of laterals on emitter clogging using wastewater and groundwater for irrigation. Results of this study revealed that besides water quality, the type of emitter, placement of laterals, and emitter position on laterals affected emitter's clogging. The major cause of clogging was associated with the precipitated substance accumulated at the emitter inlet concurrently close the micro-pore channels of the emitter, consequently reduce the emitter discharge. The major substances that took part in the clogging of emitter were EC, pH, HCO3, Turbidity, total solid, Escherichia coli (E. coli), and total coliform. It was observed that these substances (HCO3, Turbidity, total solid, E. coli, and total coliform) of groundwater and wastewater were categorized with a medium risk of clogging except for magnesium (low risk of clogging). Pressure compensating drip emitter showed better performance against clogging as compared to non-pressure compensating drip emitter. Sub-surface placement of drip emitter was more prone to clogging under both wastewater and groundwater. It was observed a significant (p ≤ 0.05) effect of lateral placement, emitter types, and the interaction between these factors on emitter's clogging under both types of water. Emitter flow rate decreased with the increasing time of operation of the drip systems at normal operating pressure, because of clogging of emitters. By flushing operation, it was observed a 3 to 5% higher flow rate in inline drip emitter than bioline (1-2%). The R2 value, which precisely describes the head-discharge relationship, was high (0.99) in most of the bioline treatments. This study also observed and recommended that pressure compensating emitter would be the most appropriate technique to reduce the clogging while using wastewater for irrigation. Flushing effectively controlled the emitter's clogging thus improved the emitter's water discharge rate.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

New analytical solution for the study of hydraulic interaction between Alpine tunnels and groundwater

2003 ◽  
Vol 174 (5) ◽  
pp. 441-448 ◽  
Author(s):  
Jean-Christophe Maréchal ◽  
Pierre Perrochet
Keyword(s):  
Analytical Solution ◽  
Surface Waters ◽  
Discharge Rate ◽  
Water Discharge ◽  
Rate Condition ◽  
Type Curves ◽  
Discharge Rates ◽  
The Alps ◽  
Surface Monitoring ◽  
Tunnel Discharge

Abstract The present paper addresses two major problems encountered during tunnel drilling and related to the hydraulic interaction with surrounding groundwater bodies. The first one is the prediction of water discharge into the tunnel, as a function of the geometric and hydrogeological data. The second problem is related to the assessment of the draining effects on surface waters (springs, lakes, wetlands). Surface monitoring campaigns are costly and evaluating their duration is a sensitive question. Both problems are tightly related and depend on aquifer dynamics. It is shown that in a geological context with steeply dipping structures, nearly vertical, inducing series of aquifers and aquicludes such as in the Alps, the drainage of the aquifer by the tunnel can be modelled by the analytical solution of Jacob and Lohman [1952] for artesian wells. First developed for horizontal, confined unsteady flow towards a vertical well with constant drawdown, it is adapted here to a horizontal tunnel by a rotation of π/2. The main difference between this solution and more classical Theis’ solutions is that a constant drawdown condition replaces the constant discharge rate condition. Hence, a relation is obtained for the time-dependent discharge rate Q(t) detected at the tunnel after drilling, as a function of aquifer transmissivity (T), storage coefficient (S), initial drawdown (so) and tunnel radius (ro). This analytical solution is compared to a finite-elements model simulating a draining tunnel in a simplified 2D vertical cross-section. The comparisons show that the decay of the tunnel discharge can be divided into two periods. During the first period, radial drawdown develops around the tunnel and there is excellent match between analytical and numerical results. Tunnel discharge results from the decompression of rock and water (storage effects) as a response to the sudden initial drawdown at the tunnel location. During the second period, the drawdown cone reaches the aquifer limits (lateral and upper) and numerical discharge rates decrease faster than analytical rates because of hydraulic heads decline at the aquifer limits. In the Alps, such trends were observed for the discharge rates into the Simplon and Mont-Blanc tunnels, and the analytical solution of Jacob and Lohman [1952] was applied to the first discharge period to evaluate aquifer transmissivity and storage coefficients. As indicated by the simulations, and corroborated by field observations, the analytical solution is only valid during a first period after tunnel opening, the duration of which scaling with the inverse of the aquifer diffusivity (T/S). In the second part of the paper, dimensionless type-curves are presented to enable rapid evaluation of the time where a given drawdown is observed at a given distance from the tunnel. Accounting for tunnel geometry (radius and depth) and aquifer parametres (T and S), these curves could for instance help in practice to determine when surface waters would start to be affected by a draining tunnel underneath. Although neglecting the boundary effects discussed in the first part of the paper, these type-curves demonstrate the great inertia of mountain aquifers, and could be used to adjust the duration of surface monitoring campaigns according to the specific tunnel/aquifer settings.

scholarly journals Thermal Characteristics Analysis on Multi- Heat Pipe Induced Heat Exchanger

2019 ◽  
Vol 9 (2S2) ◽  
pp. 143-147 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pipe ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cold Water ◽  
Hot Water ◽  
Working Fluid ◽  
Physical Parameters

In this investigation of multi heat pipe induced in heat exchanger shows the developments in heat transfer is to improve the efficiency of heat exchangers. Water is used as a heat transfer fluid and acetone is used as a working fluid. Rotameter is set to measure the flow rate of cold water and hot water. To maintain the parameter as experimental setup. Then set the mass flow rate of hot water as 40 LPH, 60LPH, 80 LPH, 100LPH, 120 LPH and mass flow rate of cold water as 20 LPH, 30 LPH, 40 LPH, 50 LPH, and 60 LPH. Then 40 C, 45 ºC, 50 ºC, 55 C, 60 ºC are the temperatures of hot water at inlet are maintained. To find some various physical parameters of Qc , hc , Re ,, Pr , Rth. The maximum effectiveness of the investigation obtained from condition of Thi 60 C, Tci 32 C and 100 LPH mhi, 60 LPH mci the maximum effectiveness attained as 57.25. Then the mhi as 100 LPH, mci as 60 LPH and Thi at 40 C as 37.6%. It shows the effectiveness get increased about 34.3 to the maximum conditions.

scholarly journals EAST RIVER BATTLE FOR SHEEN: SKIMMING AN OIL SHEEN IN A 3- TO 5-KNOT CURRENT

2001 ◽  
Vol 2001 (2) ◽  
pp. 1431-1434
Author(s):  
Dennis E. Connelly ◽  
Dennis J. McCarthy ◽  
John E. Westerlind
Keyword(s):  
New York ◽  
Current Flow ◽  
Discharge Rate ◽  
Water Discharge ◽  
Cooling Water ◽  
High Discharge ◽  
East River ◽  
Discharge Canal ◽  
High Discharge Rate ◽  
Set Up

ABSTRACT This paper explores the challenges involved with the recovery of oil from a discharge canal with limited access and high relative currents. In March 1999, a sheen was observed in the cooling water discharge canal of Consolidated Edison's 2.5-million kilowatt generating station in Queens (New York City), New York At the time the sheen was discovered, the entire station had been shut down for several months for a maintenance outage. As the tide rose and fell in the East River, into which the discharge canal emptied, the oil sheen moved in and out of a 1,000-foot long tunnel connecting the generating station to the canal. The major challenges to the recovery and removal of the oil sheen were: (1) the low over head of the discharge tunnel and canal support girders, which prevented getting a skimmer into the tunnel and canal; (2) the high discharge rate of the station's cooling water pump; and (3) skimming the sheen in a 3-to 5-knot current. Consolidated Edison is a member of Clean Harbors Cooperative, L.L.C, which was brought in to remove the sheen. This was accomplished utilizing two JBF Scientific DIP Belt Skimmers, which were set up parallel to the current flow, and deflection booming.

scholarly journals Critically Ill vs. Non-Critically Ill Patients With COVID-19 Pneumonia: Clinical Features, Laboratory Findings, and Prediction

2021 ◽  
Vol 11 ◽  
Author(s):  
Wandong Hong ◽  
Qin Chen ◽  
Songzan Qian ◽  
Zarrin Basharat ◽  
Vincent Zimmer ◽  
...  
Keyword(s):  
Critical Illness ◽  
Disease Severity ◽  
Critically Ill ◽  
Clinical Features ◽  
Critically Ill Patients ◽  
Interleukin 6 ◽  
Discharge Rate ◽  
Laboratory Data ◽  
Laboratory Findings ◽  
Laboratory Parameters

ObjectivesThe objective of this study was to investigate the clinical features and laboratory findings of patients with and without critical COVID-19 pneumonia and identify predictors for the critical form of the disease.MethodsDemographic, clinical, and laboratory data of 63 COVID-19 pneumonia patients were retrospectively reviewed. Laboratory parameters were also collected within 3–5 days, 7–9 days, and 11–14 days of hospitalization. Outcomes were followed up until March 12, 2020.ResultsTwenty-two patients developed critically ill pneumonia; one of them died. Upon admission, older patients with critical illness were more likely to report cough and dyspnoea with higher respiration rates and had a greater possibility of abnormal laboratory parameters than patients without critical illness. When compared with the non-critically ill patients, patients with serious illness had a lower discharge rate and longer hospital stays, with a trend towards higher mortality. The interleukin-6 level in patients upon hospital admission was important in predicting disease severity and was associated with the length of hospitalization.ConclusionsMany differences in clinical features and laboratory findings were observed between patients exhibiting non-critically ill and critically ill COVID-19 pneumonia. Non-critically ill COVID-19 pneumonia also needs aggressive treatments. Interleukin-6 was a superior predictor of disease severity.

Suppression of Sheet Cavitation Inception by Water Discharge Through Slit

1987 ◽  
Vol 109 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Hiroharu Kato ◽  
Hajime Yamaguchi ◽  
Shinzo Okada ◽  
Kohei Kikuchi ◽  
Masaru Miyanaga
Keyword(s):  
Boundary Layer ◽  
Flow Visualization ◽  
Discharge Rate ◽  
Water Discharge ◽  
Cavitation Inception ◽  
Suppression Effect ◽  
Sheet Cavitation ◽  
Effect Of Water

This paper studies experimentally the suppression effect of water discharge on incipient and developed sheet cavitation on a hemispherical headform. The water is discharged tangentially from a slit upstream of a cavitating region into the boundary layer on the headform. Increasing the discharge rate, the length of the sheet cavity becomes shorter and then the cavity is suppressed completely. Flow visualization test shows the generation of wavy motion in the boundary layer which disturbs the separated zone, resulting in disappearance of the sheet cavitation.

Clear-water local scour at wide piers in shallow-water flow

2014 ◽  
Vol 9 (3) ◽  
pp. 331-343 ◽  
Author(s):  
N. Ahmad ◽  
T. Mohamed ◽  
F. H. Ali ◽  
B. Yusuf
Keyword(s):  
Laboratory Data ◽  
Local Scour ◽  
The Other ◽  
Scour Depth ◽  
Temporal Development ◽  
Clear Water ◽  
Shallow Water Flow ◽  
Equilibrium Time ◽  
Sediment Size ◽  
Flow Intensity

Laboratory data for local scour depth regarding the size of wide piers are presented. Clear water scour tests were performed for various pier widths (0.06, 0.076, 0.102, 0.14 and 0.165 m), two types of pier shapes (circular and rectangular) and two types of uniform cohesionless bed sediment (d50 = 0.23 and d50 = 0.80 mm). New data are presented and used to demonstrate the effects of pier width, pier shape and sediment size on scour depth. The influence of equilibrium time (te) on scouring processes is also discussed. Equilibrium scour depths were found to decrease with increasing values of b/d50. The temporal development of equilibrium local scour depth with new laboratory data is demonstrated for flow intensity V/Vc = 0.95. On the other hand, the results of scour mechanism have shown a significant relationship between normalized volume of scoured and deposited with pier width, b. The experimental data obtained in this study and data available from the literature for wide piers are used to evaluate predictions of existing methods.

A diffusion process model for the optimal operation of a reservoir system

1975 ◽  
Vol 12 (4) ◽  
pp. 859-863 ◽  
Author(s):  
Stanley R. Pliska
Keyword(s):  
Optimal Control ◽  
Diffusion Process ◽  
Process Model ◽  
Discharge Rate ◽  
Water Discharge ◽  
Optimal Operation ◽  
Water Levels ◽  
Control Problems ◽  
Release Rates ◽  
Controlled Diffusion

The water level in a reservoir is modelled as a controlled diffusion process on a compact interval of the real line. The problem is to control the water discharge rate so as to minimise the expected costs, which depend upon the histories of the water levels and release rates. The form of the optimal control is studied for two general classes of reservoir control problems.

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