Giles Wiggs Sheffield Centre for International Drylands Research Aeolian dune processes and dynamics 2004 Joint Assembly Montreal, Canada.

Slides:

Advertisements

Similar presentations

Subgrid-Scale Models – an Overview

Advertisements

1B Clastic Sediments Lecture 28 BEDFORMS IN COHESIONLESS SUBSTRATE Structure of bedforms Formative conditions Unidirectional and Oscillating flows NH

Focus: Detecting vortices/turbulence in pure superfluid 4 He at T

EART163 Planetary Surfaces Francis Nimmo. Last Week – Impact Cratering Why and how do impacts happen? –Impact velocity, comets vs. asteroids Crater morphology.

Sediment Transport Outline

ON WIDTH VARIATIONS IN RIVER MEANDERS Luca Solari 1 & Giovanni Seminara 2 1 Department of Civil Engineering, University of Firenze 2 Department of Environmental.

Scaling of viscous shear zones with depth dependent viscosity and power law stress strain-rate dependence James Moore and Barry Parsons.

Gaseous And Particulate Dispersion In Street Canyons

UNIVERSITY OF SOUTH CAROLINA Erosion rate formulation and modeling of turbidity current Ao Yi and Jasim Imran Department of Civil and Environmental Engineering.

Results It was found that variations in wettability disturb the flow of adjacent liquid (Fig. 3). Our results suggest that for a given liquid the normal.

Morphodynamic Equilibria in Tidal Embayments with Decreasing Cross-Section Henk Schuttelaars The Institute for Marine and Atmospheric research Utrecht.

PTYS 554 Evolution of Planetary Surfaces Aeolian Processes I.

National Center for Earth-surface Dynamics Modeling physical and ecological dynamics of channel systems that shape Earth’s surface Moving boundary problems.

Eddy Covariance John Knowles University of Colorado Department of Geography INSTAAR.

CE 230-Engineering Fluid Mechanics Lecture # 28 Laminar flow in circular pipes.

CROSS-SHORE TRANSPORT

WP4: Safety and Performance for Innovative Reactor Systems 3 rd Annual Meeting, Imperial College London, 9 th April 2008 Reynolds-Averaged Navier-Stokes.

James Sprittles ECS 2007 Viscous Flow Over a Chemically Patterned Surface J.E. Sprittles Y.D. Shikhmurzaev.

Models of Turbulent Angular Momentum Transport Beyond the  Parameterization Martin Pessah Institute for Advanced Study Workshop on Saturation and Transport.

Computational Investigations of Gravity and Turbidity Currents Eckart Meiburg UC Santa Barbara Motivation Governing equations / computational approach.

DETAILED TURBULENCE CALCULATIONS FOR OPEN CHANNEL FLOW

Airflows and the spread of airborne pathogens in the ICU Dr Collette W

HYDRAULICS AND SEDIMENT TRANSPORT: RIVERS AND TURBIDITY CURRENTS

1 A combined RANS-LES strategy with arbitrary interface location for near-wall flows Michael Leschziner and Lionel Temmerman Imperial College London.

Generalized Entropy and Transport Coefficients of Hadronic Matter Azwinndini Muronga 1,2 1 Centre for Theoretical Physics & Astrophysics Department of.

Viscous hydrodynamics and the QCD equation of state Azwinndini Muronga 1,2 1 Centre for Theoretical Physics and Astrophysics Department of Physics, University.

Viscous hydrodynamics and Transport Models Azwinndini Muronga 1,2 1 Centre for Theoretical Physics and Astrophysics Department of Physics, University of.

Groundwater 1 Groundwater flows slowly through the voids between grains or the cracks in solid rock. Much of our knowledge depends on field and laboratory.

Effects of Upwind Roughness Changes and Impacts on Hub-Height Winds Peter A. Taylor 1,2, Wensong Weng 1 and James R. Salmon 2 1 Centre for Research in.

Rheological Controls on Strain Partioning during Continental Extension (When does E=MC 2 ?) Chris Wijns, Klaus Gessner, Roberto Weinberg, Louis Moresi.

Sediment Transport over Ripples and Dunes Stephen R McLean, UC Santa Barbara Jonathan Nelson, USGS, Denver, CO Thanks to: Sandro Orlandi, University of.

Suspended Load Bed Load 1. Bedload Transport transport rate of sediment moving near or in contact with bed particles roll or hop (saltate), with grain-to-grain.

Direct Numerical Simulation of Particle Settling in Model Estuaries R. Henniger (1), L. Kleiser (1), E. Meiburg (2) (1) Institute of Fluid Dynamics, ETH.

Turbulent properties: - vary chaotically in time around a mean value - exhibit a wide, continuous range of scale variations - cascade energy from large.

Towards a evaluation of a tensor eddy-diffusivity model for the terra incognita grey gray zone Omduth Coceal 1, Mary-Jane Bopape 2, Robert S. Plant 2 1.

Mass Transfer Coefficient

Gesa-Partner 8 East-Macedonia Thrace – Participants: Prof N Kotsovinos, Prof. C Koutitas,, Prof. V Hrissanthou, and the M.Sci. Eng. A. Georgoulas,A Samaras,

General Description of coastal hydrodynamic model.

Evaluation of shear stress computation at a tidal inlet using different methods A. Pacheco, J.J. Williams, Ó. Ferreira, J.A. Dias.

ISIS18 Rouen 2008 An Analytical Solution of Weak Mach Reflection (1.1 < M i < 1.5) by John M. Dewey University of Victoria, Canada.

Reynolds Analogy It can be shown that, under specific conditions (no external pressure gradient and Prandtle number equals to one), the momentum and heat.

Measuring Mars sand flux seasonality and calibrating the threshold for sand mobility F. Ayoub, J-P. Avouac, C.E. Newman, M.I. Richardson, A. Lucas, S.

1 A unified description of ripples and dunes in rivers 5 m Douglas Jerolmack, Geophysics, MIT; With David Mohrig and Brandon McElroy.

Sediment Transport Modelling Lab. The Law of the Wall The law of the wall states that the average velocity of a turbulent flow at a certain point is proportional.

Computational Modeling of 3D Turbulent Flows With MC2 Claude Pelletier Environment Canada MSC / MRB.

Interaction between vortex flow and microturbulence Zheng-Xiong Wang （王正汹） Dalian University of Technology, Dalian, China West Lake International Symposium.

Weakly nonlinear analysis of dunes by the use of a sediment transport formula incorporating the pressure gradient Satomi Yamaguchi (Port and airport Institute,

Basic sediment transport

Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: A Reduced-Order Model of the Mean Properties of a Turbulent Wall Boundary Layer.

turbulent open channel flow

Introduction to the Turbulence Models

Development of the two-equation second-order turbulence-convection model (dry version): analytical formulation, single-column numerical results, and.

The Role of Grain Dynamics in the Onset of Sediment Transport

Introduction Donghyuk Shin from U. of Edinburgh

Dynamics & Mass transfer modelling Application Observations

K-ε model, ASM model.

Date of download: 10/26/2017 Copyright © ASME. All rights reserved.

WHAT CONTROLS BAR MIGRATION IN TIDAL CHANNELS?

C. F. Panagiotou and Y. Hasegawa

Intro to Global Modeling and Prediction Session

Intermittency and clustering in a system of self-driven particles

Nonlinear channel-shoal dynamics in long tidal embayments

Exercise 1: Fenton River Floodplain Exercise

Introduction Donghyuk Shin from U. of Edinburgh

Subgrid-Scale Model Tests Using Petascale Computers

Fluid properties 1.

Turbulent Kinetic Energy (TKE)

Turbulent properties:

Low Order Methods for Simulation of Turbulence in Complex Geometries

Aeolian Processes I.

Presentation transcript:

Giles Wiggs Sheffield Centre for International Drylands Research Aeolian dune processes and dynamics 2004 Joint Assembly Montreal, Canada

Dunes in equilibrium…. Best 1993

Measurements of mean windspeed and sediment transport McKenna-Neumann et al 1997 Wiggs 2001 windspeed sand flux

Lancaster et al 1996 Measurements of shear velocity U*U* Wiggs 2001 mean shear velocity shear stress turbulence

Measurements of Reynolds turbulent stress Reynolds stress Streamline angle

Calibration of numerical models Parsons et al 2004

Other modelling approaches - complex systems Werner 1995 Momiji et al 2000 Baas 2002

Other modelling approaches - analytical solutions ( Hersen, Sauermann, Herrmann, Andreotti) Schwammle & Herrmann 2003 Hersen 2004

Hersen et al 2004 Output sand flux Dune width

Dunes in dis-equilibrium….? Parker Gay Jr 1999 Hersen 2004

Conclusions 1.dune research is in a healthy state! 2.measurements of airflow structure improving BUT requires improved understanding of turbulence / sediment transport relationships 3.calibration of computational models allowing greater understanding of form/flow interactions 4.results of analytical models suggest a requirement for more fieldwork focusing on:  dynamics of sediment transfers at the dune and inter-dune scale  longer time-series measurements of dune evolution