Flow physics of radiatively heated particle-laden channel flow and simulation methods for shock-driven problems in materials with strength

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Simulations of multiphase flows are used to understand and predict a wide variety of natural and industrial phenomena. This thesis concerns simulations of two different multiphase flows. The first part of this thesis uses high fidelity simulations to study particle-laden turbulent channel flow, subjected to strong radiation heating. Chapter 2 describes the physics of isothermal particle- laden channel flow, characterizing the effects of particles on turbulence across wide parametric variation in Stokes number and mass loading. Ideas from other branches of turbulence study, in particular compressible turbulence and rough-wall turbulence, are applied to make progress toward a model for two-way coupled particle-laden channel flow. Chapter 3 considers the dynamics of particle clouds in isothermal particle-laden channel flow using new tessellation based approaches to characterize particle clustering, rotation, and swirling motions. The dependence of the particle dynamics is characterized as function of Stokes number and mass loading, but also flow region, and comparisons with previous results from homogeneous isotropic turbulence are made in the logarithmic layer. Finally, the effect of strong radiation heating is shown on particle-laden channel flow in chapter 4. The strong heat transfer drives expansion and acceleration, and the flow tends towards re-laminarization from acceleration and viscosity increase. The second part of this thesis describes the development of an Eulerian finite difference method for simulating multi-phase mixtures of elastic-plastic materials subjected to shock waves and undergoing strain hardening. The new method uses localized artificial diffusivity (LAD) to regularize discontinuities, including discontinuities in strain, which are important in shocks in solids. New LAD terms are added to stabilize the kinematic evolution equations in strong shear deformation. The new method is tested on a variety of 1D and 2D problems to demonstrate its convergence properties, ability to simulate impacts, and shock capturing ability. The 2D problems considered are a Taylor impact with realistic equation of state and plasticity models, and a solid-solid Richtmyer-Meshkov instability, which would be challenging for more traditional Lagrangian methods. Lastly, three interface sharpening techniques for multiphase flows are extended to elastic-plastic materials, and their performance is evaluated on a variety of test problems. The methods are comparable when simulations are well-resolved, but show different deficiencies when flow topologies become under-resolved.


Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2023; ©2023
Publication date 2023; 2023
Issuance monographic
Language English


Author West, Jacob Roy
Degree supervisor Lele, Sanjiva K. (Sanjiva Keshava), 1958-
Thesis advisor Lele, Sanjiva K. (Sanjiva Keshava), 1958-
Thesis advisor Farhat, Charbel
Thesis advisor Mani, Ali, (Professor of mechanical engineering)
Degree committee member Farhat, Charbel
Degree committee member Mani, Ali, (Professor of mechanical engineering)
Associated with Stanford University, School of Engineering
Associated with Stanford University, Department of Mechanical Engineering


Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Jacob Roy West.
Note Submitted to the Department of Mechanical Engineering.
Thesis Thesis Ph.D. Stanford University 2023.
Location https://purl.stanford.edu/cs354hf9578

Access conditions

© 2023 by Jacob Roy West
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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