home   about me   research   publications   software   miscellany   links 

 
 

My 2004-5 Research Statement [PDF]  
 

click on one of the images to learn about my research.  
 
low Mach number modeling

Low Mach Number Modeling of Type Ia Supernovae

in collaboration with CCSE/LBL

We have developed a new stratified low Mach number hydrodynamics algorithm, allowing for finite-amplitude density/temperature fluctuations while filtering soundwaves.
 
 
 
 

Turbulent Flames in SNe Ia

in collaboration with CCSE/LBL

turbulent flames
coming soon
 
 
 
 
bubbles

Reacting Buoyant Bubbles

in collaboration with CCSE/LBL

We are performing large scale, fully resolved studies of burning rising bubbles in both two and three dimensions in conditions appropriate to Type Ia supernovae.
 
 
 
 

3-D Reactive Rayleigh-Taylor

in collaboration with CCSE/LBL


[recent research talk]
3-D RT
Three-dimensional direct numerical simulations of carbon flames in Type Ia supernovae undergoing the Rayleigh-Taylor instability and the transition to turbulence.
 
 
 
 
Larger-Scale Flamelet Studies

Larger-Scale
Flamelet Studies

in collaboration with CCSE/LBL

Comparison of fully resolved and thickened flame models of SNe Ia RT unstable flames. We perform direct validation of the thickened-flame model to the DNS data.
 
 
 
 

Reactive Rayleigh-Taylor Instability: the Transition to Distributed Burning

in collaboration with CCSE/LBL


[recent talk on SNe Ia flames]
Reactive Rayleigh-Taylor Instability
Direct numerical simulations of Rayleigh-Taylor unstable flames in Type Ia supernovae. We simulate a range of densities capturing the transition from the flamelet regime to the distributed burning regime. These are the first multi-dimensional simulations to show this transition directly.
 
 
 
 
Landau-Darrieus Instability

Landau-Darrieus Instability

in collaboration with CCSE/LBL

A planar flame front is intrinsically unstable due to thermal expansion across the interface. We perform many simulations with different box widths and demonstrate the small scale cutoff to the growth of the instability due to the finite thickness of the flame.
 
 
 
 

SNe II Mixing

SN II Mixing
Two-dimensional, spherical AMR calculations of the post-shock mixing.
 
 
 
 
XRB
      Spreading

XRB Spreading

Multidimensional investigations into whether an XRB can ignite locally without rotation. It can't.
 
 
 
 

Flame-Vortex Interactions

in collaboration with the Flash Center

flame-vortex interactions
Studies as to whether the interaction of a thermonuclear flame with a vortex pair can locally quench the flame.
 
 
 
 
X-ray burst gallery

Helium Detonations on
Neutron Stars

(my thesis)
 

in collaboration with the Flash Center

Two-dimensional calculations of the dynamics of the explosion from my thesis. We follow the detonation wave as it propagates 2 km across the surface of the neutron star.

 

Other research:

FLASH Code

I am one of the developers of the FLASH Code (described in detail in our code paper), a parallel, AMR hydrodynamics code. FLASH solves the compressible Euler equations and can include self-gravity. We won a Gordon Bell prize in 2000 for a cellular detonation with FLASH, run on 6420 processors of the ASCI Red computer. FLASH is freely downloadable.

 

Computational Hydrodynamics

I am also working on a simple prototyping code to test out different CFD algorithms, concentrating at the moment at understanding the behavior of split vs. unsplit algorithms. Some of this is done in pyro. It is mostly a toy code, not intended for production jobs, but mainly to try different ideas out. This hydrodynamics code is written in python/C, and is available for download here.

 

1-D Flame Models

Some simple C/O flame models (using an unscreened Caughlan & Fowler 1988 reaction rate) are available for comparison. These are the same models used in Dursi et al. 2003 (submitted).

 

I/O

Previously, I worked a lot on Parallel I/O for FLASH. I've summarized some of this in a general parallel I/O tutorial.

 

Collaborators:

Most recently, I have been collaborating with Ann Almgren, John Bell, Marc Day, and Charles Rendleman at the Center for Computational Science and Engineering at Lawrence Berkeley Laboratory.

Jonathan Dursi and I frequently collaborate on problems involving astrophysical flames.

 

 

 

 

updated March 3, 2005

best viewed with Mozilla

Valid HTML 4.01!