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)....

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...

Testing Turbine Aeration for Dissolved Oxygen Enhancement
During August of 1993 the Bureau of Reclamation tested turbine aeration for dissolved oxygen (DO) enhancement at Deer Creek Powerplant near Provo, Utah. This test required a variety of...

Simultaneous Flow Visualization and Hot-Film Measurements
High-speed video recording of flow visualizations in the near wall region of a turbulent open channel flow was synchronized with hot-film measurements of flow velocity and bed shear stress...

Monitoring and Modeling the Transport of Coarse Single Particles in Mountain Rivers
The dynamics of single cobbles was studied in the alpine river Lainbach using the Magnetic Tracer Technique (MATT) and radiotransmitters (PETSY = PEbble Transmitter SYstem). Our measurements...

A Study on Mathematical Model for Sediment Yield in Mountain Regions with Large Hillside Slopes
Based on the characteristics of water and soil loss in mountain region with large hillside slopes in southwest of China, the equations of runoff formation and sediment yield are obtained....

Fluvial Hydraulics of Streams and Mountain Rivers with Mobile Bed
The local hydraulic conditions concerning the incipient motion of the bed material in mountain streams are considered. Results of measurements carried out by using the radioisotope tracer...

Energy Losses in Steep Tributary Streams at Flows Near The Threshold of Bedload Entrainment
The flow patterns in mountain tributary streams that depends on the channel morphology, cobbles, boulders and debris that protrude along the channel and bank height cause energy losses...

Thresholds for Gravel and Cobble Motion
Flows necessary to initiate motion of rocks on a lateral bar along the Gunnison River in Black Canyon of the Gunnison National Monument are observed. Gravel and cobbles are painted and...

Effects of Particle Shape on Bedload Transport
The effects of particle shape on bedload transport in gravel-bed streams are examined using a similarity approach and fractional transport analysis for data from Piceance Creek, Colorado,...

A General Theory of Channel Adjustment in High Gradient Streams
The paper presents a theory of channel adjustment in high gradient streams. This theory states that given sufficient energy, stream channels will adjust their dimensions and flow hydraulics...

A Mechanism of Pool Formation and Maintenance in Forest Streams
Laboratory and field investigations illustrate a hydraulic mechanism responsible for the formation and maintenance of pools associated with large, in-channel obstructions in forest streams....

Estimating Local Bed Shear Stress in Large Gravel-Bed Rivers
The local bed shear stress ?o1 cannot be directly measured and is typically estimated using flow observations in various theoretical or empirical...

Coarse Sediment Transport and the Maintenance of Fish Habitat in the Upper Colorado River
An analysis of the relation between discharge and boundary shear stress is presented for an alluvial reach of the Colorado River near Grand Junction, CO. The analysis indicates that the...

Boundary Shear in the Vicinity of River Banks
Some experimental data are presented concerning the distribution of boundary shear stresses in trapezoidal open channels for both inbank and overbank flows. The local shear stresses on...

Determination of Geometry and Stress Distribution of an Optimal Stable Channel
A numerical model which determines the geometry of a threshold channel was recently developed (Diplas and Vigilar, 1992). This is important in the design of irrigation canals, channelization...

Field Evaluation of the Sediment Transport Model Stream with a Bank Erosion Component
The graded sediment routing and stream bed evolution model STREAM of Borah, Alonso and Prasad was expanded earlier by incorporating a riverbank erosion component of Osman and Thorne. In...

Carpet Flow Analysis
Under very high flow conditions, sediment may be transported either in a suspension or by carpet flow, as defined by Bagnold. This study examines the theoretical conditions for carpet...

Investigation of an Anisotropic k-? Model
In this paper the eddy viscosity hypothesis is abandoned and explicit expressions of Reynolds stress are deduced directly from the transport equations. Anisotropic k and ? equations are...

Design and Testing of Two Ice-Preserving Winter Lake Aeration Systems
As part of an effort to achieve ice-preserving lake aeration for winterkill prevention, two non-mixing lake aeration systems were designed and field tested. Each creates a fish refuge...

 

 

 

 

Return to search