Interfacial Dynamics of Ferrofluids in Hele-Shaw Cells- [electronic resource]
Interfacial Dynamics of Ferrofluids in Hele-Shaw Cells- [electronic resource]
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214101909
- ISBN
- 9798380718639
- DDC
- 551.63
- 저자명
- Yu, Zongxin.
- 서명/저자
- Interfacial Dynamics of Ferrofluids in Hele-Shaw Cells - [electronic resource]
- 발행사항
- [S.l.]: : Purdue University., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(157 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-05, Section: B.
- 주기사항
- Advisor: Christov, Ivan C.
- 학위논문주기
- Thesis (Ph.D.)--Purdue University, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약Ferrofluids are remarkable materials composed of magnetic nanoparticles dispersed in a carrier liquid. These suspensions exhibit fluid-like behavior in the absence of a magnetic field, but when exposed to a magnetic field, they can respond and deform into a variety of patterns. This responsive behavior of ferrofluids makes them an excellent material for applications such as drug delivery for targeted therapies and soft robots. In this thesis, we will focus on the interfacial dynamics of ferrofluids in Hele-Shaw cells. The three major objectives of this thesis are: understanding the pattern evolution, unraveling the underlying nonlinear dynamics, and ultimately achieving passive control of ferrofluid interfaces. First, we introduce a novel static magnetic field setup, under which a confined circular ferrofluid droplet will deform and spin steadily like a 'gear', driven by interfacial traveling waves. This study combines sharp-interface numerical simulations with weakly nonlinear theory to explain the wave propagation. Then, to better understand these interfacial traveling waves, we derive a long-wave equation for a ferrofluid thin film subject to an angled magnetic field. Interestingly, the long-wave equation derived, which is a new type of generalized Kuramoto- Sivashinsky equation (KSE), exhibits nonlinear periodic waves as dissipative solitons and reveals fascinating issues about linearly unstable but nonlinearly stable structures, such as transitions between different nonlinear periodic wave states. Next, inspired by the lowdimensional property of the KSE, we simplify the original 2D nonlocal droplet problem using the center manifold method, reducing the shape evolution to an amplitude equation (a single local ODE). We show that the formation of the rotating 'gear' arises from a Hopf bifurcation, which further inspires our work on time-dependent control. By introducing a slowly time-varying magnetic field, we propose strategies to effectively control a ferrofluid droplet's evolution into a targeted shape at a targeted time. The final chapter of this thesis concerns our ongoing research into the interfacial dynamics under the influence of a fast timevarying and rotating magnetic field, which induces a nonsymmetric viscous stress tensor in the ferrofluid, requiring the balance of the angular momentum equation. As a consequence, wave propagation on a ferrofluid interface can be now triggered by magnetic torque. A new thin-film long-wave equation is consistently derived taking magnetic torque into account.
- 일반주제명
- Skewness.
- 일반주제명
- Propagation.
- 일반주제명
- Vortices.
- 일반주제명
- Drug delivery systems.
- 일반주제명
- Mathematical models.
- 일반주제명
- Nanoparticles.
- 일반주제명
- Magnetic fields.
- 일반주제명
- Robots.
- 일반주제명
- Fluids.
- 일반주제명
- Energy.
- 일반주제명
- Thin films.
- 일반주제명
- Interfaces.
- 일반주제명
- Electromagnetics.
- 일반주제명
- Nanotechnology.
- 일반주제명
- Pharmacology.
- 일반주제명
- Physics.
- 일반주제명
- Robotics.
- 기타저자
- Purdue University.
- 기본자료저록
- Dissertations Abstracts International. 85-05B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.