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Multiphysics Flow Simulation Group

Current Funded Projects

Simulation of the Effects of Convection and Radiation on Pyrolysis and Ignition of Moist Live Fuels

Faculty: Babak Shotorban and Shankar Mahalingam

Students: Selina Ferguson and Bangalore Yashwanth

Collaborators: David R. Weise (Pacific Southwest Research Station, USDA Forest Service), Thomas H. Fletcher (Brigham Young University), Sara S. McAllister (RMRS-Fire Sciences Lab-Missoula), and William M. Jolly (RMRS-Fire Sciences Lab-Missoula)

Funded by United States Department of Agriculture

Higher-Order Two-Fluid Methods for Simulations of Particle-Laden Flow

Faculty: Babak Shotorban

Student: Quang Truong (San Diego State University)

Collaborator: Gustaaf Jacobs (San Diego State University)

Funded by National Science Foundation

In this research, a high-order two-fluid method is formulated based on a new set of coupled two-fluid PDEs and a higher-order numerical method. The two-fluid model is obtained from the first principles utilizing an Eulerian approach for the description of particles. In the Eulerian frame, the particle phase is modeled through a set of Eulerian transport equations obtained from the Liouville equation governing the fine-grained probability density function of particle properties. The transport equations are discretized through a high-order resolution, hybrid multidomain WENO-spectral method. The high-resolution method is projected to improve over existing lower-order method by capturing discontinuous interfaces and shocks sharply, while accurately resolving small scale, unsteady particle-laden flow features. The focus of this proposal is on the formulation of a stable and consistent capturing of discontinuous particle-gas interfaces as well as a stable and consistent source coupling between the particle and gas phases.

A Fundamental Investigation of Fire Initiation and Fire Behavior in Sparse Vegetation

Faculty: Shankar Mahalingam and Babak Shotorban

Students: Ambarish Dahale and Satyajeet Padhi

Collaborator: Thomas H. Fletcher (Brigham Young University)

Funded by National Science Foundation

The purpose of this collaborative research project is to develop advanced modeling technology for describing fire initiation and propagation in vegetation with low canopy bulk density. The ability to predict the spread of wildland fires is paramount in protecting life, property, and natural resources. Detailed physical models, at either laboratory or landscape scale, require improved sub-grid scale models of combustion, especially to describe fire behavior in vegetation that does not act like a dense fuel bed due to the relative sparseness of the vegetation. This technology will be based on fundamental combustion measurements of live fuels, but it will apply to models of landscape-scale fires. The research objective will be achieved via four inter-related tasks: (1) flame propagation measurements in live leaves and small branches, (2) fire spread measurements in shrubs for varying bulk densities, (3) flame propagation models of bushes and trees, and (4) multi-bush fire behavior models. The research will provide a cohesive picture of the phenomenon of fire spread starting from ignition of a single fuel element, such as a leaf, to a self-sustaining fire spreading through a larger fuel array such as a forest. The fundamental physical and chemical processes investigated are also relevant to the problem of surface fire propagation leading to ignition of crown fires. Gaining an understanding of the conditions under which a fire may or may not propagate within a sparse vegetative fuel bed will provide understanding of how to control fire spread more effectively in these fuel types through improved fuel management.

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Animation: Crown fuel is Chamise shrub with moisture content of 31.5 %. Flames are represented by isosurfaces of gas-phase temperature equal to 500 K.

Past Funded Projects

Exploring The Role of Fuel Moisture on Pyrolysis Gas Flame Structure and Its Influence on Fire Behaviour

Faculty: Shankar Mahalingam and Babak Shotorban

Student: Selina Ferguson

Funded by United States Department of Agriculture

Stochastic Charge Fluctuations of Dust Particles with Time-varying Currents in Plasmas

Faculty: Babak Shotorban

Funded by UAH through Junior Faculty Distinguished Rsearch Award

Uncertainty Quantification of Turbulence Models with High-performance Computing

Faculty: Babak Shotorban

Funded by UAH through Junior Faculty Distinguished Rsearch Award

Nonisothermal Large-eddy Simulation of Particle-laden Turbulent Flows through Equilibrium Eulerian Approachs

Faculty: Babak Shotorban

Funded by UAH through Research Mini-Grant Award

A Robust Two-fluid Approach for Direct Simulation of Particle-laden Flows

Faculty: Babak Shotorban

Funded by UAH through Research Mini-Grant Award