- Author
- Ezekoye, O. A. | Zhang, Z.
- Title
- Modeling of Combustion, Fluid Mechanics and Radiation in Turbulent Buoyant Fires. Annual Report. September 15, 1995-September 15, 1996.
- Coporate
- University of Texas, Austin
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- Annual Report, 1996, 51 p.
- Keywords
- combustion models | fluid mechanics | microgravity | jet flames | diffusion flames | soot | kinetics | radiation modeling | oxidation | fire safety | safety engineering | vapor phases | fire models | fire physics
- Identifiers
- microgravity burner flames; initial and boundary conditions; effects of OH oxidation (experimental comparisons); effects of coagulation model (soot surface area estimates; variable gas absorption coefficients
- Abstract
- The development of appropriate strategies for fire safety engineering will rely upon both experimental and computational data on fires. Adequate computational formulations of fire physics are still very much in the development stages. For fire modeling, this includes the combustion processes and also some aspects of the radiative transfer phenomena. In the three years that our research program here at the University of Texas (UT) has been funded by NIST, we have implemented a complete combustion model within a Lagrangian flamelet model. Phenomenological chemistry models for the Lagrangian flamelet were replaced over time by more fundamental chemical modeling strategies. The inclusion of more detailed chemical kinetics into the investigation has been very profitable with respect to our understanding of chemistry-soot-radiation interactions (a topic which has not received much consideration within the fire/combustion community). Our results clarify the role of finite rate chemistry effects in radiative extinction processes. We reported on the validity of the state-relationships concept for moderately sooting diffusion flames. The level of detail with respect to transport processes in our simulations allowed us to investigate subtle features of these flames such as the effects of species diffusivities on the burning rates, C/H ratio and species universality in mixture fraction space. We then considered somewhat larger laboratory scale diffusion flame computations. In these studies we have simulated a microgravity diff11sion flame and have begun simulations of fully elliptic jet diffusion flames.