Computational Research

 

Fires

While fire has been around since the beginning of man, we still have much to learn about it. The challenge in "predicting" fire is the highly coupled transport processes of chemical reactions and radiation heat transfer in a turbulent mixing buoyancy driven flow.

 

Multi-phase blast waves

Damage from accidental non-ideal explosions occur in flour mills, coal mines, etc.  Non-ideal explosions do not follow “classical” scaling laws due to the role of multiphase turbulent mixing processes that defines ignition delay. 


This is a simulation of a fully coupled fluid-structure in a reacting flow. Fuel is emitted out of the letter "C", mixed with air using letter "E", reacts and heats letter "T".

Algorithm development

Finite element descriptions of structures are coupled with finite volume formations of the flow field using a ghost-cell based, immersed interface method. Within the context of our JAVA framework, this allows for coupling of multiple FE objects to simultaneously exist in the flow solutions space. Coupling objects include in-house and ABAGUS FE models. Our research code framework, "Simulate It (SIMIT)", is written entirely in JAVA.

 

Flame Spread

A fully coupled 2D fluid–solid direct numerical simulation (DNS) approach is used to simulate co-flow flame spread over PMMA. Comparison of simulations and experimental measurements are conducted over a range of flame spread rates. Upon heating, materials release volatile gases that will then burn and, in-turn heat additional surfaces creating a feedback cycle leading to the phenomena of flame spread. 

 

Combustion Chamber Design

The practical design of combustion chambers requires the consideration of optimal turbulent mixing of fuel and oxidizer for greater efficiency. Through the secondary combustion of pyrolysis products and combustor geometry changes, numerical simulations of turbulent flow is explored in a two-stage wood burning hydronic heater.

 

Radiation Heat transfer

A major challenge in describing the radiation heat transfer is that it is wavelength dependent, i.e. energy is transferred differently for different wavelengths. This is especially difficult in multiphase flows where scattering of the radiant energy is highly dependent on the wavelength. The image shows how radiant energy is absorbed by a water droplet as a function of size and wavelength using Mie scattering theory.