Chaotic Advection in a Shear Layer
The developing (in time) inviscid shear layer, although not yet in its turbulent regime, displays all the characteristics of chaotic advection. The corresponding Lyapunov exponent is strictly...
Computation of Flow Fields Induced by Hydroplant Releases into Lower Lock Approaches
A turbulence-based computational procedure was developed and applied to the prediction of flow fields in navigation installations induced by hydropower releases. The procedure uses a depth-averaged...
On Determination of Turbulence Model Coefficients for Anisotropic Reynolds Stress Closure Model
In this paper, the determination of turbulence model coefficients for anisotropic Reynolds stress model is discussed. The proposed model includes anisotropic Reynolds stress modeling and...
Spatial Coherence in the Chaotic Dynamics of Multi-Degree-of-Freedom Elastic Impact Oscillators
In this paper, we describe a method for estimating the number of degrees of freedom needed to adequately model nonlinear structural systems. We apply the method to the study of chaotic...
Hydrodynamic Behavior of Cohesive Sediments in Turbulent Flow
To meet both engineering and basic research requirements, a series of experiments on the deposition of cohesive soil were conducted in an annular rotating fiberglass channel-ring system...
Mechanics of Cohesionless Sediment Transport in Coastal Waters
Conceptual mechanics-based models for sediment transport processes in steady and unsteady turbulent boundary layer flows are derived and discussed. To the extent possible the predictions...
Turbulence Measurements and Parameterizations
Bottom boundary layer and exchange models account for high frequency turbulence via Reynold's averaging and the most advanced closure formulations required by this averaging...
Turbulence Modelling of Suspended Sediment in the Surf Zone
A computational model is developed for the prediction of the wave period averaged turbulence structure under a breaking wave. The principal forcing function for the model is the generation...
Influence of Hydrodynamics on Biofilm Accumulation
The influence of hydrodynamics on biofilm thickness was investigated under laminar and turbulent flow conditions. The maximum biofilm thickness was found within the transition region between...
Calculation of Three-Dimensional Turbulent Flow in Francis Turbine Runner
A numerical scheme, based on MacCormack's predictor-corrector explicit finite volume method, for solving three-dimensional weakly compressible inviscid, laminar, and turbulent...
Development of a New Hydraulic Design Tool for Spiral Casing/Distributor Geometry
A novel computational model has been developed to predict highly complex turbulent flow in a combined spiral casing/distributor geometry. Validation of the computational model against...
Numerical Modeling of Air/Water Mixtures for Internal Flows
The Tennessee Valley Authority (TVA) currently is working with several organizations to develop design tools for the aerating hydroturbine. Part of this effort includes the investigation...
Investigations on 3-D Flow Structures in Combined Systems of Groynes and Harbour Basins
The structure of the flow field in harbour basins shows significant three-dimensional (3-D) effects, e.g. variation of the direction of the horizontal velocity components with depth, existence...
Turbulence and Reynolds Stress Distribution in a Natural River
Turbulence characteristics of ambient flow velocities and their comparison with those generated by the movement of barge traffic within the channel border area in a navigation waterway...
The Effect of Surface Films on Concentration Fluctuations Close to a Gas/Liquid Interface
Modeling of gas/liquid mass transport requires knowledge concerning the behavior of near-surface concentration fluctuations at clean and film-covered gas/liquid interfaces. Previous measurements...
Hydrodynamics and Mass Transfer in a Jet-Agitated Vessel
Experiments of carbon dioxide absorption in water have been carried out in a turbulent vessel presenting a zero mean shear stress value at the gas-liquid interface. Liquid-phase turbulence...
Effect of Temperature on Gas Transfer at Low Surface Renewal Rates
In order to investigate the dependence of gas transfer coefficients on temperature under conditions of low surface renewal rates, laboratory experiments were conducted using simultaneous...
Turbulent Water Aeration: Analytical Approach and Experimental Data
Analytical studies based on the statistical theory of turbulence were carried out in order to identify some relevant parameters which may be associated with the reaeration rate coefficient...
Turbulent Velocity and Gas Concentration Measurements in the Near-Surface Layer
An experiment was undertaken to study the mechanism of interfacial mass transfer. Near-surface liquid turbulence and oxygen concentration fluctuations have been measured in a grid-stirred...
Development of Method for Measuring Near-Surface Turbulence
New techniques for tracking particles in fluid are presented. A method to make micro-capsules which are filled with pure water and covered with a thin film of polystyrene is developed....
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