On Measurements of Particle Spinning Motion
Investigation of particle saltation motion is crucial to the development of the theory of bed load transport. Due to the combination effects of the bed roughness and the velocity gradient,...
Hot-Film Response in Three-Dimensional Highly Turbulent Flows
A methodology is described for accurate turbulence measurements with hot film or hot wires even at turbulent intensities as high as 100%. The assumptions involved and the approximations...
Experimental Study on Turbulent Structures in Unsteady Open-channel Flows
Turbulence measurements in unsteady open-channel flows over smooth beds were conducted accurately by the simultaneous use of two-component LDA system and water-wave gauges. In the inner...
Response of Velocity and Turbulence to Abrupt Changes from Smooth to Rough Beds in Open-channel Flows
Response of velocity distribution and turbulence characteristics to abrupt changes of bed roughness have been investigated experimentally with two-component laser Doppler anemometer (LDA)....
Optical Methods for Sediment-Laden Flows
A method of distinguishing between the signals from the liquid-seed particles and sediment particles, while using LDV in sediment-laden flows, is described. The validity of the method...
Estimation of Mean Velocity for Flow Under Ice Cover
Methods of estimating mean velocity in a vertical from point velocity measurements are compared for an ice-covered channel. The comparison is based on velocity profiles obtained from a...
Effects of Simulated Ice on the Performance of Price Type-AA Current Meter Rotors
Slush ice readily adheres to the standard metal rotor of the winter Price type-AA current meter and affects the ability of the meter to measure the flow velocity accurately. Tests conducted...
Developing Air Concentration and Velocity Probes for Measuring Highly-Aerated, High-Velocity Flow
The U.S. Bureau of Reclamation's stepped spillway overtopping protection research program required velocity and air concentration profile data be obtained during testing in a large, 15.2-m-high...
Application of a Needle Probe in Measuring Local Parameters in Air-Water Flow
In this paper, development of a double needle probe for measuring local parameters in air-water mixtures is explained. This probe is designed to measure flow velocities up to 10 m/s and...
Anomalous Measurements in a Compound Duct
An anomalous velocity distribution on the 'flood plain' of a compound duct is reported and discussed. The tentative conclusion is that the phenomenon is to be explained by the co-existence...
Recent Applications of Acoustic Doppler Current Profilers
A Broadband acoustic Doppler current profiler (BB-ADCP) is a new instrument being used by the U.S. Geological Survey (USGS) to measure stream discharge and velocities, and bathymetry....
Field Performance of an Acoustic Scour-Depth Monitoring System
The Herbert C. Bonner Bridge over Oregon Inlet serves as the only land link between Bodie and Hatteras Islands, part of the Outer Banks of North Carolina. Periodic soundings over the past...
Comparison of Current Meters Used for Stream Gaging
The U.S. Geological Survey (USGS) is field and laboratory testing the performance of several current meters used throughout the world for stream gaging. Meters tested include horizontal-axis...
LDV System for Towing Tank Applications
The design, construction, testing, and operation of a two-dimensional LDV system for use in a towing tank is described. The primary design considerations were underwater application, minimal...
Coherent Structures in Compound Open-Channel Flows by Making Use of Particle-Tracking Visualization Technique
In this study, images of very small 100 ?m diameter particles uniformly suspended in compound open-channel flows were recorded on an optic disc using a high-sensitive CCD camera and 2W...
Practical Method for Scour Prediction at Bridge Piers
A practical method is presented for prediction of local scour at bridge piers which is based on a comparison of many well known equations and supported by field data. This equation includes...
Practical Method for Calculating Contraction Scour
Total scour at bridge crossing waterways consists of long-term aggradation or degradation of the streambed, contraction scour and local scour at the piers and abutments. This paper will...
Brief Summary of National Bridge Scour Data Base
This paper briefly summarizes more than 470 measurements of local channel scour at bridge piers from 58 sites in 14 States. Relations between local scour and selected deterministic parameters...
Ultimate Depth of Scour Around Bridge Piers
A design equation for estimating ultimate depth of local scour at bridge piers has been proposed which is based upon the envelope curves drawn to published field data covering a wide range...
Kent, Edward
In order to perform conservative scour analyses for coastal bridge sites it is necessary to develop realistic hydraulic simulations which provide worst case estimates of depth and velocity....
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