# Roman V. Samulyak, Ph.D.

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Associate Professor

Department of Applied Mathematics and Statistics

Stony Brook University

### Presentation

*Simulations of Multiphase Magnetohydrodynamic Flows for Nuclear Fusion Applications*

New mathematical models, numerical algorithms, and computational software for the study of multiphase plasma flows at low magnetic Reynolds numbers in the presence of phase transitions and external energy sources have been developed. The governing system of equations include a coupled hyperbolic - elliptic system in geometrically complex, evolving domains and equations for phase transitions and external sources. Numerical algorithms use the method of front tracking for material interfaces, high resolution hyperbolic solvers, the embedded boundary method for the elliptic problem in evolving domains, new EOS and electrical conductivity models, and kinetic models for external sources. Algorithms are multiscale as they use subgrid models and special grids for processes occurring at different scales. They have been implemented as an MHD extension of FronTier, a hydrodynamic code with free interface support.

The software is being used for the simulation of MHD processes occurring in nuclear fusion and particle accelerator applications. The simulation of the ablation of cryogenic deuterium pellets in the process of fueling of tokamaks will be discussed. In our recent work, the pellet ablation rate and lifetime in magnetic fields were systematically studied for the first time and compared with theory and existing experimental databases. Simulations revealed several new features of the pellet ablation and made predictions for future experiments in the International Thermonuclear Experimental Reactor (ITER). Work in progress on the plasma liner driven magnetized target fusion will also be discussed.

### Biography

Dr. Samulyak holds a joint appointment as an Associate Professor at the AMS Department, Stony Brook University, and Scientist at the Computational Science Center, Brookhaven National Laboratory. He received his Ph. D. in Applied Mathematics from New Jersey Institute of Technology / Rutgers University. He joined the Brookhaven Laboratory after graduation and worked there for 8 years. R. Samulyak conducted research in mathematical modeling, numerical algorithms, and simulations of complex physics processes in particle accelerators and nuclear fusion and fission applications. He served as the principal investigator for several Department of Energy (DOE) funded projects. After joining Stony Brook University in 2007, R. Samulyak continues research in the area of numerical algorithms and large scale computing.