scholarly journals An Empirical V-notch Weir Equation and Standard Procedure to Accurately Estimate Drainage Discharge

2021 ◽  
Vol 37 (6) ◽  
pp. 1097-1105
Author(s):  
Md Sami Bin Shokrana ◽  
Ehsan Ghane
Keyword(s):  
Flow Rate ◽  
Control Structure ◽  
Standard Procedure ◽  
Subsurface Drainage ◽  
Flow Equation ◽  
Accurate Estimation ◽  
List Type ◽  
Flow Meter ◽  
Weighing Method ◽  
Sharp Crest

HighlightsAn empirical flow equation was developed for a metal-edge sharp-crest V-notch weir.A top-down approach was used to determine the height of the V-notch apex.A combination of the weighing method and a flow meter was used to develop the stage-discharge equation.A standard procedure was presented to accurately estimate the flow rate.Abstract. A reliable empirical flow equation for V-notch weirs will provide flow estimates that can be used to calculate nutrient loads leaving fields with subsurface drainage. The objective of this study was to develop such an equation for an AgriDrain metal-edge sharp-crest 45° V-notch weir. In this undertaking, we measured flow rate with a combination of the weighing method for low flow and a turbine flow meter for high flow. The head of water (H) was measured inside a 25-cm AgriDrain control structure with a three-step method. First, we measured the water level (a) and height of the control structure (b). Second, we measured the height of the V-notch apex (c). Third, we calculated head using this equation: H= (b-a) – (b-c). Based on the flow meter readings (Q) and H measurements, we developed the following stage-discharge equation: Q = 0.749H 2.25, with Q in liters per minute and H in centimeters. This equation is valid for an H less than the height of the V-notch (i.e., flow through the V-notch) with unsubmerged flow. Based on field experience, we provide a standard procedure for accurate estimation of drainage discharge. In conclusion, the stage-discharge equation developed in this study can provide reliable flow estimates for subsurface drainage studies. Keywords: Flow rate, Metal-edge weir, Sharp-crest weir, Subsurface drainage, Tile drainage, Weir placement.

Investigation of saturation flow rate using video camera at signalized intersections in Jordan

2020 ◽  
Vol 11 (1) ◽  
pp. 216-226
Author(s):  
Bara’ W. Al-Mistarehi ◽  
Ahmad H. Alomari ◽  
Mohamad S. Al Zoubi
Keyword(s):  
Flow Rate ◽  
Standard Procedure ◽  
Video Camera ◽  
Signalized Intersections ◽  
Speed Limit ◽  
Local Conditions ◽  
Highway Capacity Manual ◽  
Saturation Flow Rate ◽  
Turning Radius ◽  
Saturation Flow

AbstractThis study aimed to investigate a potential list of variables that may have an impact on the saturation flow rate (SFR) associated with different turning movements at signalized intersections in Jordan. Direct visits to locations were conducted, and a video camera was used. Highway capacity manual standard procedure was followed to collect the necessary traffic data. Multiple linear regression was performed to classify the factors that impact the SFR and to find the optimal model to foretell the SFR. Results showed that turning radius, presence of camera enforcement, and the speed limit are the significant factors that influence SFR for shared left- and U-turning movements (LUTM) with R2 = 76.9%. Furthermore, the presence of camera enforcement, number of lanes, speed limit, city, traffic volume, and area type are the factors that impact SFR for through movements only (THMO) with R2 = 69.6%. Also, it was found that the SFR for LUTM is 1611 vehicles per hour per lane (VPHPL),which is less than the SFR for THMO that equals to 1840 VPHPL. Calibration and validation of SFR based on local conditions can improve the efficiency of infrastructure operation and planning activities because vehicles’ characteristics and drivers’ behavior change over time.

scholarly journals Research on the impact of ship traffic flow on the restricted channel segment of the middle Yangtze River based on traffic wave theory

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Ting Liu ◽  
Gabriel Lodewijks
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Flow Simulation ◽  
Wave Theory ◽  
Flow Density ◽  
List Type ◽  
Ship Traffic ◽  
Traffic Wave ◽  
The Impact ◽  
Channel Segment

Abstract Abstract On the basis of the influence of dry season on ship traffic flow, the gathering and dissipating process of ship traffic flow was researched with Greenshields linear flow—density relationship model, the intrinsic relationship between the ship traffic congestion state and traffic wave in the unclosed restricted channel segment was emphatically explored when the ship traffic flow in a tributary channel inflows, and the influence law of multiple traffic waves on the ship traffic flow characteristics in unclosed restricted segment is revealed. On this basis, the expressions of traffic wave speed and direction, dissipation time of queued ships and the number of ships affected were provided, and combined with Monte Carlo method, the ship traffic flow simulation model in the restricted channel segment was built. The simulation results show that in closed restricted channel segment the dissipation time of ships queued is mainly related to the ship traffic flow rate of segments A and C, and the total number of ships affected to the ship traffic flow rate of segment A. And in unclosed restricted channel segment, the dissipation time and the total number of ships affected are also determined by the meeting time of the traffic waves in addition to the ship traffic flow rate of segments. The research results can provide the theoretical support for further studying the ship traffic flow in unclosed restricted channel segment with multiple tributaries Article Highlights The inflow of tributaries' ship traffic flows has an obvious impact on the traffic conditions in the unenclosed restricted channel segment. The interaction and influence between multiple ship traffic waves and the mechanism of generating new traffic waves are explained. The expression of both dissipation time of queued ships and the total number of ships affected in the closed and unclosed restricted channel segment are given.

Evaluation of Design Characteristics for Animal Mortality Composting Systems

2021 ◽  
Vol 65 (1) ◽  
pp. 23-30
Author(s):  
Tiago Costa ◽  
Neslihan Akdeniz
Keyword(s):  
Moisture Content ◽  
Linear Relationship ◽  
Compressive Stress ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Airflow Rate ◽  
List Type ◽  
Design Characteristics ◽  
The Impact ◽  
Composting Systems

HighlightsDesign characteristics for animal mortality compost cover materials were tested.Compressive stress was applied to simulate the effects of the mortalities on cover materials.The highest permeability was measured for sawdust at 25% moisture content.A linear relationship was found between the volumetric flow rate and the power required to aerate the piles.Abstract. Composting is an aerobic process that relies on natural aeration to maintain proper oxygen levels. Air-filled porosity, mechanical strength, and permeability are among the essential parameters used to optimize the process. This study’s objective was to measure the physical parameters and airflow characteristics of three commonly used cover materials at four moisture levels, which could be used in designing actively aerated swine mortality composting systems. A laboratory-scale experiment was conducted to measure pressure drops across the cover materials as a function of the airflow rate and the material’s moisture content. Compressive stress was applied for 48 h to simulate the impact of swine mortalities on the cover materials. The power required to aerate each material was determined as a function of volumetric flow rate and moisture content. As expected, air-filled porosity and permeability decreased with increasing bulk density and moisture content. The highest average permeability values were measured at 25% moisture content and ranged from 66 × 10-4 to 70 × 10-4 mm2, from 161 × 10-4 to 209 × 10-4 mm2, and from 481 × 10-4 to 586 × 10-4 mm2 for woodchips, ground cornstalks, and sawdust, respectively. For the range of airflow rates tested in this study (0.0025 to 0.0050 m3 s-1 m-2), a linear relationship (R2 = 0.975) was found between the volumetric flow rate (m3 s-1) and the power required to aerate the compost pile (W per 100 kg of swine mortality). Keywords: Airflow, Darcy’s law, Livestock, Modeling, Permeability, Pressure drop.

RATIONALIZATION OF THE UNIT FOR DIAGNOSING THE FLOW RATE OF HYDRAULIC EQUIPMENT FOR MOBILE MACHINES

2020 ◽  
Author(s):  
A.N. Sirotenko ◽  
◽  
S.A. Partko
Keyword(s):  
Flow Rate ◽  
Strength Analysis ◽  
Sensor Design ◽  
Flow Meter ◽  
Threaded Connection ◽  
Hydraulic Equipment ◽  
Mobile Machine

The article presents a strength analysis of the flowmeter design used in the diagnostics nodes of mobile machine hydraulic units. The connection of the flow meter housing with the bracket has been simplified and adapted for a more robust sensor design, taking into account the strength and tightness of the threaded connection. The tightness of the applied sealing method is confirmed by the analysis of the stressstrain state of the connection parts and confirmed practically.

Accuracy of resting metabolic rate prediction equations among healthy adults in Trinidad and Tobago

2020 ◽  
pp. 026010602096623
Author(s):  
Selby Nichols ◽  
Dennora George ◽  
Patrice Prout ◽  
Nequesha Dalrymple
Keyword(s):  
Metabolic Rate ◽  
Standard Procedure ◽  
Resting Metabolic Rate ◽  
Demographic Variables ◽  
Overweight And Obesity ◽  
Accurate Estimation ◽  
Prediction Equations ◽  
The Caribbean ◽  
The University ◽  
Adult Volunteers

Background: Over 50% of adults in Latin America and the Caribbean have a body mass index (BMI) ≥ 25 suggesting excess energy intakes relative to energy expenditure. Accurate estimation of resting metabolic rate (RMR), the largest component of total energy requirements, is crucial to strategies aimed at reducing the prevalence and incidence of overweight and obesity. Aim: We evaluated the accuracies of established and locally developed RMR prediction equations (RMRP) among adults. Methods: Four hundred adult volunteers ages 20 to 65 years had RMR measured (RMRM) with a MedGem® indirect calorimeter according to recommended procedures. RMRP were compared to RMRM with values ± 10% of RMRM deemed accurate. Anthropometry was measured using standard procedure. Linear regression with bootstrap analyses was used to develop local RMRP equations based on anthropometric and demographic variables. The University of the West Indies Ethics Committee approved the study. Results: Males had higher mean absolute RMR ( p < 0.001) but similar mean age-adjusted measured RMR per kg of body (20.9 vs. 21.5 kcals/day; p = 0.1) to females. The top performing established anthropometry-based RMRP among participants by sex, physical activity (PA) level and BMI status subgroups were Mifflin-St Jeor, Owen, Korth, Harris–Benedict, and Livingston, while Johnstone, Cunningham, Müller (body composition (BC)), Katch and McArdle, Mifflin-St Jeor (BC) were the most accurate BC-based RMRP. Locally developed RMRP had accuracies comparable to their top-ranked established RMRP counterparts. Conclusions: Accuracies of established RMRP depended on habitual PA level, BMI status, BC and sex. Furthermore, locally developed RMRP provide useful alternatives to established RMRP.

scholarly journals Calibration of Stainless Steel-edged V-Notch Weir Stop Logs for Water Level Control Structures

2019 ◽  
Vol 35 (5) ◽  
pp. 745-749
Author(s):  
L. E. Christianson ◽  
R. D. Christianson ◽  
A. E. Lipka ◽  
S. Bailey ◽  
J. Chandrasoma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Water Level ◽  
Flow Rate ◽  
Subsurface Drainage ◽  
Conservation Practices ◽  
Nutrient Loads ◽  
Level Control ◽  
Control Structures ◽  
Flow Monitoring ◽  
Flow Through

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.

Research on the Vortex Mass Flow Meter of Dual Bluff Body Based on Differential Pressure Principle

2013 ◽  
Vol 401-403 ◽  
pp. 1110-1113
Author(s):  
Quan Sheng Duan ◽  
Li Cui Wang
Keyword(s):  
Lower Limit ◽  
Mass Flow ◽  
Flow Rate ◽  
Bluff Body ◽  
Differential Pressure ◽  
Low Flow ◽  
Body Structure ◽  
Measurement Sensitivity ◽  
Flow Meter ◽  
Pressure Signal

The lower limit of the existing vortex mass flow meter based on differential pressure is high. So the application of the existing vortex mass flow meter is limited in the measurement for low flow rate. This paper proposes a method using vortex mass flow meter of dual bluff body based on differential pressure principle. The differential pressure signal between the upstream and downstream can be amplified by the vortex overlap caused by the dual bluff body structure. The results of the simulation by Fluent show that this method can reduce the lower limit of measurement, and improve the measurement sensitivity effectively.

Sequential Control of Multichannel On–Off Valves for Linear Flow Characteristics Via Averaging Pulse Width Modulation Without Flow Meter: An Application for Pneumatic Valves

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Kanchit Pawananont ◽  
Thananchai Leephakpreeda
Keyword(s):  
Flow Rate ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Single Channel ◽  
Flow Characteristics ◽  
Volumetric Flow Rate ◽  
Operating Conditions ◽  
Mean Flow ◽  
Flow Meter ◽  
Linear Flow

Control of on–off valves for linear flow characteristics is a challenging design problem due to nonlinearity of valve mechanism and fluidic properties under various operating conditions. In this study, averaging pulse width modulation (PWM) is proposed as a control valve signal by implementing PWM with predetermined duty period so that overflow at the open position and underflow at the closed position are divided proportionately around desired mean flow rates during entire cycle periods. Multichannels in a parallel pattern are implemented to yield linear flow characteristics with higher resolution than a single channel. With pressure and temperature measurements, the volumetric flow rate is determined by an empirical model of flow characteristics across flow control valves at given operating conditions. The experimental results on achieving the desired volumetric flow rate of air under actual flow conditions without a flow meter are presented for viability of the proposed methodology in practical uses.

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