Experimental investigations and numerical simulations for an open channel flow of a weak elastic polymer solution around a T-profile

2004 ◽  
Vol 36 (3) ◽  
pp. 408-418 ◽  
Author(s):  
C. Balan ◽  
V. Legat ◽  
A. Neagoe ◽  
D. Nistoran
Keyword(s):  
Numerical Simulations ◽  
Polymer Solution ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Experimental Investigations ◽  
Elastic Polymer

Interaction of surface waves with turbulence: direct numerical simulations of turbulent open-channel flow

1995 ◽  
Vol 286 ◽  
pp. 1-23 ◽  
Author(s):  
Vadim Borue ◽  
Steven A. Orszag ◽  
Ilya Staroselsky
Keyword(s):  
Free Surface ◽  
Numerical Simulations ◽  
Channel Flow ◽  
Gravity Waves ◽  
Open Channel ◽  
Open Channel Flow ◽  
Surface Region ◽  
Direct Numerical Simulations ◽  
Turbulence Production ◽  
Wind Sea

We report direct numerical simulations of incompressible unsteady open-channel flow. Two mechanisms of turbulence production are considered: shear at the bottom and externally imposed stress at the free surface. We concentrate upon the effects of mutual interaction of small-amplitude gravity waves with in-depth turbulence and statistical properties of the near-free-surface region. Extensions of our approach can be used to study turbulent mixing in the upper ocean and wind–sea interaction, and to provide diagnostics of bulk turbulence.

Solids Distribution in Sediment-Laden Open-Channel Flow: Experiment and Prediction

2020 ◽  
Author(s):  
Václav Matoušek ◽  
Jan Krupička ◽  
Tomáš Picek ◽  
Štěpán Zrostlik
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Transport Model ◽  
Plane Surface ◽  
Open Channel Flow ◽  
Solid Particles ◽  
Experimental Results ◽  
Transport Layer ◽  
Experimental Investigations ◽  
Solids Concentration

Abstract Solid-liquid flow is studied in an open channel with a mobile bed at the condition of intense transport of solids. It is flow of high-concentrated mixture of coarse sediment and water over a plane surface of the bed eroded due to high bed shear. In the flow, solid particles are non-uniformly distributed across the flow depth. The flow develops a transport layer, adjacent to the the top of the bed, in which transported particles interact with each other. Results are presented of experimental investigations of the sediment-laden open-channel flow in a recirculating titling flume. The experiments included measurements (using ultrasonic techniques) of the distribution of solids velocity across the transport layer. The related distribution of solids concentration was deduced from the measured distribution of velocity and from other measured flow quantities. Since recently, a direct measurement of the solids distribution across the transport layer has been added to the experiments using a measuring technique svideo camera and a laser sheet. This work discusses results of combined measurements of the distributions of solids concentration and velocity in steady uniform turbulent flow for two lightweight solids fractions and various flow conditions (a broad range of the bed Shields parameter, discharge of solids, discharge of mixture, and the longitudinal slope of the bed). Furthermore, the camera-based measuring method and the deducing method for a determination of solids distribution are discussed and their results compared to show a good agreement in a majority of the test runs. The experimental results are compared with predictions of a recently developed bed-load transport model. Among other outputs, the model predicts the position of the top of the transport layer and the local velocity of sediment particles at this position. The presented model predictions agree well with experimental results based on the measured distibutions.

RELIABILITY OF 5-BEAM LDV FIBEROPTIC PROBE FOR TURBULENCE MEASUREMENTS IN THE WALL REGION OF OPEN-CHANNEL FLOW

2009 ◽  
Vol 16 (3) ◽  
pp. 255-277 ◽  
Author(s):  
Giancarlo Alfonsi ◽  
Samuele de Bartolo ◽  
Roberto Gaudio ◽  
Leonardo Primavera
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Wall Region ◽  
Turbulence Measurements ◽  
Fiberoptic Probe

MODELING THE ORGANIC REMOVAL AND OXYGEN CONSUMPTION BY BIOFILMS IN AN OPEN-CHANNEL FLOW

1994 ◽  
Vol 30 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Shiyu Li ◽  
Guang Hao Chen
Keyword(s):  
Water Quality ◽  
Oxygen Consumption ◽  
River Water ◽  
Channel Flow ◽  
Diffusion Layer ◽  
Open Channel ◽  
Open Channel Flow ◽  
River Water Quality ◽  
Monod Kinetics ◽  
Organic Removal

A mathematical model is proposed to predict the removal of dissolved organic substances and the consumption of dissolved oxygen by attached biofilms in an open-channel flow. The model combines the biofilm equations with the conventional Streeter–Phelps type equations of river water quality by considering the mass transfer of organics and oxygen in the river water through the diffusion layer into the biofilm. It is assumed that the diffusion and reaction within the biofilm are of steady-state, and follow Monod kinetics. The model is solved numerically with a trial-and-error method. The simulation results of the model for an ideal case of river flow and biofilm show that the organic removal rate and oxygen consumption rate caused by the biofilm are greater than that by suspended biomass. The effects of diffusion layer thickness, flow velocity, and biofilm thickness on the change of river water quality are discussed.

scholarly journals Stability of Horizontal Vortices in Compound Open Channel Flow and Their 3-D Structure.

1995 ◽  
pp. 131-142 ◽  
Author(s):  
Syunske Ikeda ◽  
Nobuyoshi Murayama ◽  
Takeshi Kuga
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow
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