Chemical evolution of stellar plasma is one of the most critical components of computational models in stellar astrophysics. Nuclear abundance distributions resulting from chains of nuclear reactions serve as a key comparison tool against observations, used to further constrain models. To that end, we focus on improving the accuracy of model abundances. In most cases, abundances are obtained in the course of hydrodynamic simulations performed on Eulerian meshes. Unfortunately, those models are subject to the unphysical mixing of nuclear species due to numerical diffusion effects. For more reliable nucleosynthesis calculations, mass motions are described using passively advected Lagrangian tracer particles. These particles represent fluid elements, recording their thermodynamic histories which are subsequently used to drive detailed nucleosynthesis calculations in a post-processing procedure performed with large number of relevant isotopes. Accuracy of nucleosynthesis calculations strongly depends on the accurate coupling between fluid represented on the Eulerian mesh and tracer particles. The coupling involves both interpolation of Eulerian data to particles as well as integrating equations of motion of particles. Both steps contribute numerical errors resulting in divergence of particle tracks from fluid streamlines. Here we propose a new particle advection scheme driven by only the hydrodynamics, replacing the interpolation step of particle motion and show preliminary results. We also introduce an interpolation method for mapping our post-processed nucleosynthesis results back onto our Eulerian mesh. Spatial convergence studies are performed for the Eulerian hydrodynamic nucleosynthesis results and the remapped, post-processed Lagrangian results using a reactive Hawley-Zabusky flow. / A Dissertation submitted to the Department of Scientific Computing in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / July 16, 2018. / Astrophysics, Nucleosynthesis, Particle Meshes, Supernovae / Includes bibliographical references. / Tomasz Plewa, Professor Directing Dissertation; Mark Sussman, University Representative; Gordon Erlebacher, Committee Member; Sachin Shanbhag, Committee Member; Ming Ye, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_650685 |
| Contributors | Boehner, Philip Scott (author), Plewa, Tomasz (professor directing dissertation), Sussman, Mark (university representative), Erlebacher, Gordon, 1957- (committee member), Shanbhag, Sachin (committee member), Ye, Ming (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Scientific Computing (degree granting departmentdgg) |
| Publisher | Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text, doctoral thesis |
| Format | 1 online resource (134 pages), computer, application/pdf |
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