




Email: ffden@uaf.edu 

Email: ffraw1@uaf.edu 

Graduate Students 

Debasmita Samaddar 
Turbulence modeling and the Interaction Between Sheared Flows and Turbulence 

Oralee Nudson 
Agent Based Modeling of Complex Infrastructures 

Seth Underwood 
Dynamics of Flows in Nanotubes 

Brian Wilson 




Graduated Aug. 2004 and relocated to a land down under 

Email: ryan@timehaven.org 

Email: fsjpk@uaf.edu 


Email: fssgr@uaf.edu 

Current or recent Undergraduate Students 

Power Systems Network 

Now at Dartmouth (Grad. School in Physics) John Broussard 

Email: fsjcb1@uaf.edu 
Now at Univ. of Illinois (Grad. School in Physics) Keiko Ino 

Email: keikoroppi@hotmail.com 

Email: 
Abel
Bult 
IABUAF 
Uma
Bhatt 
IARCFrontier
at UAF 
Ben
Carreras 

Pat
Diamond 
UCSD 
Ian
Dobson 
UWMadison,
ECE 
Mark
Gilmore 
UCLA 
Carlos
Hidalgo 

Matt
Hitchman 
UWMadison 
JeanNoel
Leboeuf 
UCLA 
Kenneth
Showalter 
West
Virginia University 
Maria
Varela 
ORNL 
Boudewijn
Ph. van Milligen 

Andrew
Ware 
Univ.
of Montana 




Graduate Students 

Erin
Boyd 
IBM 
Ryan Woodard 
New Zealand 
Undergraduate Students 

Keiko Ino 
Univ. of
Illinios (Grad. School in Physics) 
Sumire Kobayashi 
Dartmouth
(Grad. School in Physics) 
John Broussard 
Dartmouth
(Grad. School in Physics) 
Aaron
Boyd 
Univ.
of Colorodo  Boulder 
David
Benbennik 
Cornell
University (Grad. School in Math) 
Andy
Lester 

Haiyin
Chen (at ORNL) 
1) Dynamics and Control of SOC Systems (Sandpiles, Power Transmission, Communications, Traffic, Plasmas)
Motivated by the complicated dynamics observed in simulations and experiments of gradient driven turbulent transport, a simple paradigmatic transport model based on the ideas of self organized criticality (SOC) has been developed and investigated . In many cases a strong coupling exists between the turbulence and bulk flows in the system. If the bulk flows are uniform the turbulence imbedded in the flow is simply advected and the dynamics are usually not changed. Often however, such flows are spatially dependent (sheared) and therefore can have an impact on the dynamics of the system. SOC systems have been the focus of much investigation recently due to the broad relevance of many of the characteristics of these systems. For example, 1/f noise is a ubiquitous feature in many diverse physical systems from starlight flicker through river flows to stock market data. Additionally many of these systems (and others) exhibit a remarkable spatial and temporal selfsimilar structure. The physical and dynamical selfsimilarity that is exhibited by these systems is very robust to perturbations and is not necessarily close to any "linearly marginal" state such as the angle of repose for a sandpile. It is this selfsimilarity and non linear self organization that leads to the term "SelfOrganized Criticality". In many systems (magnetically confined plasmas for example) the transport of constituents down their ambient gradient is thought to be dominated by turbulent transport. That is a turbulent relaxation of the gradient. The turbulence itself is often driven by the freeenergy in the gradient . It is this combination of turbulent relaxation removing the source of free energy thereby turning off the turbulence which then allows the gradient to build back up which allows the development of robust (albeit fluctuating) profiles. The dynamics of such systems can be computationally investigated with a cellular automata model of a running sand pile. This model allows us to investigate the major dynamical scales and the effect of an applied sheared flow on these dominant scales. In addition to allowing the paradigmatic investigation of turbulent transport, the introduction of sheared flow (wind) and the determination of transport coefficients in sandpiles, both of which naturally arise in the context of magnetically confined plasmas, act as a novel and important extension to the chaotic dynamics of SOC systems.Recent papers in this area (in PDF format)
Power systems (HICSS2001 Data analysis paper 1 , HICSS2001 Modeling paper 1 , HICSS2001 Modeling paper 2 , HICSS2002 modeling paper 1 , HICSS2002 modeling paper 2 )Communications systems ( HICSS2002 Modeling paper 1)
Basic SOC systems
Plasmas
2) The Interaction Between Sheared Flows and Turbulence
3) Basic Plasma and Fluid Turbulence
Investigations of the basic dynamics of the turbulent systems can shed light on both interesting nonlinear dynamics and real systems.
4) Modeling Transitions in Plasma Transport
Transitions to enhanced confinement regimes are very important for the success of the fusion energy program.
5) Dynamics of Atomistic Flows in Carbon Nanotubes
In nature the interaction between fluid flows and surfaces and the resultant transport due to the flows is both ubiquitous and of fundamental importance. One of the flow regimes of particular interest is that in which the fluid transitions to a turbulent flow. In this case, the transport characteristics and flow dynamics change dramatically. In addition to an enormous amount of attention given to these systems, much progress has been made in recent years on modeling and understanding the dynamics of these continuous fluid flows (CFD) using the NavierStokes equations. However, with the everincreasing interest in smaller size devices (for example, in MicroElectroMechanicalSystems  MEMS applications) an interesting new regime is encountered. This is the regime in which the distance between surfaces becomes comparable to the atomic or molecular sizes of the flowing material. While the highly "viscous" flow through irregular microporous materials has been extensively studied the basic underlying physics of the "fluid" dynamics of flows through "smooth" regular structures on this scale have yet to be characterized. In particular, the demonstration and characterization of transitions in flows on these scales will have a profound impact on the development of the new blossoming capabilities in building micro and nano scale devices and structured materials.A relevant yet simple realization of such a flow is that given by atoms flowing through carbon nanotubes. Typically, in nano scale systems, the effective viscosity is expected to be high unless, perhaps, the flow "channel" is very regular and smooth such as that found inside a carbon nanotube, for example. Investigation of these "atomistic" flows is of interest for the obvious reason that one must understand how material flows in these nanotubes if one wishes to use them. More importantly the demonstration of new flow dynamics with transitions within the tube could lead to altogether new uses. In addition, basic understanding of flows on these scales may be of relevance in the extreme boundary layer of continuous (NavierStokes) flows and may help in the design of special coatings, for example, to decrease (or increase) drag. It should be stressed that the novel aspect of this is not simply the nanoscales in the system, but rather the interaction between the atomistic flow and the very regular surface created by the nanotubes etc. This research project, which is on the cutting edge of the burgeoning field of nanotechnology, can at the same time make fundamental contributions to the underlying basic physics.
6) The Effect of Noise on Propagation in ReactionDiffusion Equations
7) Development of Higher Order Characteristic Measures of Dynamical Systems
Support from DOE under grants DEFG0399ER54551 and DEFG0300ER54599 (a young investigator award) and NSF under grant ECS0085647 are gratefully acknowledged
Many of the papers found on these pages are in pdf format. To find out more about pdf viewing or to get a free viewer for pdf documents see Adobes Acrobat Reader (for Macintosh(R), IBM AIX, Windows(R), Sun(TM) SPARC(R), HP/UX(TM), Silicon Graphics(R) and others) or Xpdf (for x86  Linux 2.0 ELF , PowerPC  AIX 4.1 , SPARC  SunOS 4.1.3 , MIPS, Ultrix 4.4 , Alpha  OSF/1 3.2 , HPPA, HPUX 9.05 , and others).
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Last changed on 28 January, 2008 .
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