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| Title | Speaker |
|---|---|
| A stochastic phase-field model determined from molecular dynamics |
Anders Szepessy |
| Location | Time and Date |
|---|---|
| RB 15, Roslagstullsbacken 15 Albanova | 2009-03-25 (Wed) 14.30-15.30 (coffee 14.15) |
| Abstract |
|---|
| The phase-field method is widely used to study evolution of
microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation modeling the dynamics of an order parameter determining the solid and liquid phases,
including also stochastic fluctuations to obtain the qualitatively correct result of dendritic side branching. I will present a method to determine stochastic phase-field models from atomistic formulations by coarse-graining molecular dynamics. It has four steps: (1) derivation of stochastic molecular dynamics from the time- indepedent Schrödinger equation; (2) a precise quantitative atomistic definition of the phase-field variable, based on the local potential energy; (3) derivation of its coarse-grained dynamics model, from microscopic Smoluchowski molecular dynamics; and (4) numerical computation of the coarse-grained model functions. |
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