scholarly journals NUMERICAL MODELLING - AN AID TO ASSESSING FIELD DATA

1976 ◽  
Vol 1 (15) ◽  
pp. 185
Author(s):  
H.P. Riedel ◽  
F.L. Wilkinson
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Western Australia ◽  
Field Data ◽  
Discharge Rate ◽  
Field Measurements ◽  
Flow Patterns ◽  
Industrial Complex ◽  
Flow Rates ◽  
The Mean

After the completion of 5 years of field measurements, complemented by extensive numerical modelling in 1974, the hydraulics of Cockburn Sound, Western Australia, are now understood in enough detail to allow the rate of exchange of water between the Sound and the ocean to be determined. Flow patterns in Cockburn Sound tend to be complicated by the superimposition of many driving influences, the most important being wind, but by using the output of a numerical model most of these patterns are predictable. Current magnitudes within Cockburn Sound have not reduced so that the rate of dispersion of effluents released by the industrial complex on the eastern side of the Sound has not changed. However, flow rates through the southern entrance to Cockburn Sound have been reduced to between 30 to 45$ of the rates which occurred prior to the causeway construction. This means that the mean discharge rate is now 570 m3/sec through the causeway bridges compared to a rate of about 1500 m3/sec before the causeway construction.

In situ creep of frozen soil, Fenghuo Shan, Tibet Plateau, China

1995 ◽  
Vol 32 (3) ◽  
pp. 545-552 ◽  
Author(s):  
B. Wang ◽  
Hugh M. French
Keyword(s):  
Key Words ◽  
Power Flow ◽  
Field Data ◽  
Field Measurements ◽  
Frozen Soil ◽  
Tibet Plateau ◽  
Soil Creep ◽  
Extreme Variability ◽  
The Mean

Field measurements of frozen soil creep in the upper 3.0 m of permafrost indicate that creep occurs in both winter and summer. Between 1992 and 1993, the mean rate of creep ranged from 0.44 cm at 1.6 m depth to 0.16 cm at 2.8 m depth but there was extreme variability. Creep parameters n and A, as defined by the power flow law, were calculated from field data. Parameter n ranged between 1.96 and 2.29 and increased with depth, while A decreased with depth. Comparisons of creep rates for different permafrost environments suggest that ground temperature largely controls the magnitude of permafrost creep. Key words : permafrost, creep parameters, Tibet Plateau.

scholarly journals Runoff Variability in the Scott River (SW Spitsbergen) in Summer Seasons 2012–2013 in Comparison with the Period 1986–2009

2016 ◽  
Vol 35 (3) ◽  
pp. 39-50 ◽  
Author(s):  
Łukasz Franczak ◽  
Waldemar Kociuba ◽  
Grzegorz Gajek
Keyword(s):  
River Runoff ◽  
Discharge Rate ◽  
High Variability ◽  
Flow Rates ◽  
Ice Melt ◽  
Glacier Ice ◽  
Runoff Variability ◽  
Daily Discharge ◽  
The Mean

Abstract River runoff variability in the Scott River catchment in the summer seasons 2012 and 2013 has been presented in comparison to the multiannual river runoff in 1986–2009. Both in particular seasons and in the analysed multiannual, high variability of discharge rate was recorded. In the research periods 2012–2013, a total of 11 952 water stages and 20 flow rates were measured in the analysed cross-section for the determination of 83 daylong discharges. The mean multiannual discharge of the Scott River amounted to 0.96 m3·s−1. The value corresponds to a specific runoff of 94.6 dm3·s−1·km2, and the runoff layer 937 mm. The maximum values of daily discharge amounted to 5.07 m3·s−1, and the minimum values to 0.002 m3·s−1. The highest runoff occurs in the second and third decade of July, and in the first and second decade of August. The regime of the river is determined by a group of factors, and particularly meteorological conditions affecting the intensity of ablation, and consequently river runoff volume. We found a significant correlation (0.60 in 2012 and 0.67 in 2013) between the air temperature and the Scott River discharge related to the Scott Glacier ice melt.

scholarly journals FLOW COMPUTATIONS NEARBY A STORM SURGE BARRIER UNDER CONSTRUCTION WITH TWO-DIMENSIONAL NUMERICAL MODELS

1986 ◽  
Vol 1 (20) ◽  
pp. 143
Author(s):  
H.E. Klatter ◽  
J.M.C. Dijkzeul ◽  
G. Hartsuiker ◽  
L. Bijlsma
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Field Data ◽  
Numerical Models ◽  
Flow Patterns ◽  
Scale Model ◽  
Energy Losses ◽  
Local Energy ◽  
Two Dimensional ◽  
Physical Scale

This paper discusses the application of two-dimensional tidal models to the hydraulic research for the storm surge barrier in the Eastern Scheldt in the Netherlands. At the site of the barrier local energy losses dominate the flow. Three methods are discussed for dealing with these energy losses in a numerical model based on the long wave equations. The construction of the storm surge barrier provided extensive field data for various phases of the construction of the barrier and these field data are used as a test case for the computation at methods developed. One method is preferred since it gives good agreement between computations and field data. The two-dimensional flow patterns, the discharge and the head-difference agree well,, The results of scale model tests were also available for comparison. This comparison demonstrated that depth-averaged velocities, computed by a two-dimensional numerical model, are as accurate as values obtained from a large physical scale model. Even compicated flow patterns with local energy losses and sharp velocity gradients compared well.

scholarly journals Numerical Modeling of Flow Field in Morning Glory Spillways and Determining Rating Curve at Different Flow Rates

2016 ◽  
Vol 2 (9) ◽  
pp. 448-457 ◽  
Author(s):  
Mohammad Reza Enjilzadeh ◽  
Ebrahim Nohani
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Numerical Modelling ◽  
Relative Error ◽  
Numerical Models ◽  
Discharge Rate ◽  
Morning Glory ◽  
Physical Models ◽  
Rating Curve ◽  
Inlet Conditions

Morning glory spillways with drop inlets are normally employed in dams built on narrow valleys or placed on steep slopes. In Iran, morning glory spillways have been commonly used in large Dam projects such as Sefidrood dam, Alborz dam, and Haraz dam. Physical models should be built to accurately determine hydraulic parameters of the flow and flow field in spillways. Establishment of a physical model involves extravagant costs and conditions that cannot be justified in some cases. Therefore, suitable numerical models can be proposed for such circumstances. Using FLOW3D numerical models, 3-dimensional numerical modelling of the flow was calibrated and validated by experimental information associated with morning glory spillway of Alborz dam and accuracy of numerical modelling was determined by relative error of numerical model. So it was attempted to determine flow pattern and control conditions of morning glory spillways in different modes using boundary conditions, inlet conditions and grid spacing of flow field and project rating curve of morning glory spillways. According to the results of numerical model, relative error of numerical modelling equals 6.4% for calculating discharge rate of the spillways. Numerical modelling error is 7.6% for determining depth parameter of the flow in spillway crest in comparison with experimental results.

scholarly journals Internal tides in the strait of Denmark

2019 ◽  
Vol 55 (3) ◽  
pp. 78-84
Author(s):  
Е. G. Morozov ◽  
D. I. Frey ◽  
S. V. Gladyshev ◽  
А. А. Klyuvitkin ◽  
А. N. Novigatsky
Keyword(s):  
Numerical Model ◽  
Internal Waves ◽  
Field Measurements ◽  
Internal Tides ◽  
Denmark Strait ◽  
Vertical Displacements ◽  
The Mean ◽  
Temperature Records ◽  
The Waves ◽  
Mean Current

Six day temperature records carried out at the three mooring levels revealed isotherm fluctuations in the Denmark Strait sill in July 2018 caused by internal waves. In addition to the field measurements, fluctuations of isopycnals were estimated on the basis of a numerical model. It was shown that the vertical displacements of water particles caused by semidiurnal internal tides are approximately 50 m in the region of the sill crossing the strait. The displacements decrease to 30 m over a distance of 100 km from the sill. The internal waves in the northern part of the strait are more intense than in the southern part because the wave propagates in the opposite direction to the mean current. In the southern part the waves and the current propagate to the south, which increases the wavelength and decreases their amplitudes.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals Groups and Individuals: Optical Flow Patterns of Broiler Chicken Flocks Are Correlated with the Behavior of Individual Birds

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 568
Author(s):  
Sabine G. Gebhardt-Henrich ◽  
Ariane Stratmann ◽  
Marian Stamp Dawkins
Keyword(s):  
Optical Flow ◽  
Broiler Chicken ◽  
Average Length ◽  
Flow Patterns ◽  
Group Level ◽  
Positive Correlation ◽  
Water Test ◽  
Mean And Variance ◽  
The Mean

Group level measures of welfare flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that the group-level optical flow patterns made by broiler flocks can be used to deliver information not just about the flock averages but also about the proportion of individuals in different movement categories. Mean optical flow provides information about the average movement of the whole flock while the variance, skew and kurtosis quantify the variation between individuals. We correlated flock optical flow patterns with the behavior and welfare of a sample of 16 birds per flock in two runway tests and a water (latency-to-lie) test. In the runway tests, there was a positive correlation between the average time taken to complete the runway and the skew and kurtosis of optical flow on day 28 of flock life (on average slow individuals came from flocks with a high skew and kurtosis). In the water test, there was a positive correlation between the average length of time the birds remained standing and the mean and variance of flock optical flow (on average, the most mobile individuals came from flocks with the highest mean). Patterns at the flock level thus contain valuable information about the activity of different proportions of the individuals within a flock.

Cadmium concentrations in kidneys of sheep and cattle in Western Australia. 1. Regional distribution

1994 ◽  
Vol 45 (4) ◽  
pp. 851 ◽  
Author(s):  
PW Morcombe ◽  
DS Petterson ◽  
HG Masters ◽  
PJ Ross ◽  
JR Edwards
Keyword(s):  
Western Australia ◽  
Geometric Mean ◽  
Regional Distribution ◽  
Adult Cattle ◽  
Agricultural Region ◽  
Wet Weight ◽  
The Mean ◽  
Winter Annual ◽  
Rate Of Accumulation ◽  
Cattle And Sheep

A sample of 4973 kidneys from sheep stratified by age and shire of origin within the Agricultural Region of Western Australia, was analysed for cadmium (Cd) content during the period August 1989 to April 1991. The geometric mean Cd concentration in the kidney of hogget ewes was 0.9 mg/kg, in 4-tooth ewes 1.47 mg/kg and in adult ewes 3.34 mg/kg on a wet weight basis. The mean Cd concentrations of either ewe or hogget flocks from different Divisions of the Agricultural Region did not differ from each other. The annual increase in Cd concentration of kidney from hogget sheep was estimated to be 0-65 mg/kg. The rate of accumulation of Cd in kidney from cattle and sheep grazing the same properties was similar. Kidneys from a sample of 354 adult cattle from the Kimberley Region and 483 aged sheep from the Pastoral Region, both areas of unimproved rangelands, had geometric mean Cd concentrations of 0.15 mg/kg and 0-31 mg/kg respectively. A higher Cd concentration in flocks from the divisions adjacent to the Agricultural Region may have resulted from the establishment of some volunteer species of winter annual pastures in the rangeland.

Sign in / Sign up

Export Citation Format

Share Document