| dc.identifier.uri | http://hdl.handle.net/11401/77255 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | The simulation campaign to model Inertial Confinement Fusion (ICF) capsules has come a long way since experiments with the potential to achieve net energy gain began in 2010. A remaining area of uncertainty is the modeling of instability growth and mixing of ablator material into the core, degrading the capsules. We explore the instability growth by applying techniques that have led to a proven track record of validation: the addition of a front tracking (FT) algorithm and physical diffusion models. For the first time, we have integrated our FT algorithm through an API into an external Rad-Hydro code FLASH, from the University of Chicago. With FT coupled into a code capable of simulating ICF experiments with a full suite of physics, we conduct a parameter study on 2D simulations in spherical geometry to explore the impact FT has on modeling the instability growth. We find the instability growth during the shock generated Richtmyer-Meshkov phase is suppressed by a lingering capsule acceleration, providing a stabilizing mechanism. Thus, FT does not impact the growth of these instabilities, since they are suppressed. We find the late time deceleration phase Rayleigh-Taylor instabilities are strongly radially dependent, occurring at inner regions of the shell, but not reaching the ablator-fuel interface. In an Eulerian simulation methodology, numerical diffusion of ablator material into the fuel is shown to penetrate far enough on reasonable computational grids, that strong instability growth captures it, amplifying the mixing. With FT coupled in, this numerical diffusion is prevented. We analyze simulations with a physical diffusion model coupled into the hydro equations to represent a physically consistent penetration of ablator material. To capture these effects, a 1D Buoyancy-Drag analysis is proposed to model the penetration of ablator material and amplification due to instability growth. We compare the 1D model, analyzed off a 1D simulation, to actual growth observed in the 2D simulations, to explore the predictive capabilities of this model. We find that ICF capsules are stable but near a performance cliff where small perturbations or coupling effects between different instability drivers has the potential to cause enough of a change in the dynamics to allow ablator material to penetrate into the hot spot. In closing, we discuss the impact of a lack of physical diffusion and FT models on the current state of ICF simulations. | |
| dcterms.available | 2017-09-20T16:52:17Z | |
| dcterms.contributor | Glimm, James | en_US |
| dcterms.contributor | Jiao, Xiangmin | en_US |
| dcterms.contributor | Samulyak, Roman | en_US |
| dcterms.contributor | Zingale, Michael. | en_US |
| dcterms.creator | Melvin, Jeremy | |
| dcterms.dateAccepted | 2017-09-20T16:52:17Z | |
| dcterms.dateSubmitted | 2017-09-20T16:52:17Z | |
| dcterms.description | Department of Applied Mathematics and Statistics | en_US |
| dcterms.extent | 121 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/77255 | |
| dcterms.issued | 2016-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:52:17Z (GMT). No. of bitstreams: 1
Melvin_grad.sunysb_0771E_12955.pdf: 6647203 bytes, checksum: 83cfe39fec9617b801116f9bcead808b (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Adiabat, Front Tracking, Inertial Confinement Fusion, Rayleigh-Taylor, Richtmyer-Meshkov | |
| dcterms.subject | Applied mathematics | |
| dcterms.title | Numerical Modeling of Hydrodynamic Instabilities and their Impact on Mix in Inertial Confinement Fusion | |
| dcterms.type | Dissertation | |
