자료유형  

 학위논문

Control Number  

0017161227

International Standard Book Number  

9798383087381

Dewey Decimal Classification Number  

621

Main Entry-Personal Name  

Thirumalaisamy, Ramakrishnan.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of California, San Diego., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

259 p.

General Note  

Source: Dissertations Abstracts International, Volume: 85-12, Section: B.

General Note  

Advisor: Bhalla, Amneet Pal Singh;Saintillan, David.

Dissertation Note  

Thesis (Ph.D.)--University of California, San Diego, 2024.

Summary, Etc.  

요약The volume penalization method (VP), a type of Fictitious Domain Method, is a widely used technique for solving partial differential equations (PDEs) in complex domains. Its applications span various fields, from fluid-structure interactions like wave energy converters, bird and insect flight, fish swimming, and cardiovascular flows, to phase change applications such as glacier melting and additive manufacturing processes. This thesis presents robust and adaptive VP techniques for simulating non-isothermal phase-changing flows, as well as isothermal multiphase fluid-structure interaction problems. Using the numerically constructed flux-forcing functions for arbitrarily complex boundaries, we extend the flux-based volume penalization (VP) method to handle more general boundary conditions, including spatially varying inhomogeneous Neumann and Robin boundary conditions. Several two- and three-dimensional test examples, including flux-driven thermal convection in a concentric annular domain, are considered to assess the spatial accuracy of the numerical solutions. In addition, we propose a projection method-based preconditioning strategy for solving VP incompressible and low-Mach Navier-Stokes equations. The solver converges faster as the penalty coefficient decreases, contrary to prior experience. The developed preconditioning strategy is used in a novel low Mach enthalpy method to solve solidification and melting problems with variable thermophysical properties, including density. The proposed method captures the density change-induced flow during phase change material (PCM) melting and solidification. A gas phase is also incorporated and coupled to the solid-liquid PCM region in this formulation. The new low Mach enthalpy method is validated against analytical solutions for a PCM undergoing a large density change during its phase transition. Furthermore, we propose a set of simple sanity checks to serve as benchmarks for evaluating computational fluid dynamics (CFD) algorithms that aim to capture the volume change effects of PCMs. Adaptive mesh refinement is employed to achieve fine grid resolution in domains requiring more accuracy, such as PCM-gas and liquid-solid interfaces.

Subject Added Entry-Topical Term  

Mechanical engineering.

Subject Added Entry-Topical Term  

Computational physics.

Subject Added Entry-Topical Term  

Fluid mechanics.

Subject Added Entry-Topical Term  

Aerospace engineering.

Index Term-Uncontrolled  

Fluid-structure interaction

Index Term-Uncontrolled  

Linear solvers

Index Term-Uncontrolled  

Non-isothermal multiphase flows

Index Term-Uncontrolled  

Phase change material

Index Term-Uncontrolled  

Volume penalization method

Added Entry-Corporate Name  

University of California, San Diego Mechanical and Aerospace Engineering (Joint Doctoral with SDSU)

Host Item Entry  

Dissertations Abstracts International. 85-12B.

Electronic Location and Access  

로그인을 한후 보실 수 있는 자료입니다.

Control Number  

joongbu:658489