Physics Commons^™

Oscillations Of Capillary Surfaces With Volume And Edge Effects, Dingqian Ding

All Dissertations

Capillary surfaces are defined by an interface endowed with surface tension that is partially supported by a solid substrate and are susceptible to oscillations reflecting a balance between fluid inertia and the restorative force of surface tension. The wave dynamics strongly depend upon volume change within the domain and edge effects through the boundary conditions applied at the contact-line formed at the liquid-gas-solid interface, while the spatial wave structure conforms to the geometry of the capillary surface. This dissertation develops mathematical models to address these effects for several canonical capillary surfaces, which are organized into two parts that are focused …

Controlled Manipulation And Transport By Microswimmers In Stokes Flows, Jake Buzhardt

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Remotely actuated microscale swimming robots have the potential to revolutionize many aspects of biomedicine. However, for the longterm goals of this field of research to be achievable, it is necessary to develop modelling, simulation, and control strategies which effectively and efficiently account for not only the motion of individual swimmers, but also the complex interactions of such swimmers with their environment including other nearby swimmers, boundaries, other cargo and passive particles, and the fluid medium itself. The aim of this thesis is to study these problems in simulation from the perspective of controls and dynamical systems, with a particular focus …

The Characterization Of Atmospheric Turbulence And Its Effect On Laser Beam Propagation, Michael Cox

All Theses

Having a controlled environment to measure atmospheric turbulence is essential to understanding its effects on different laser beam characteristics. The Clemson Variable Turbulence Generator (VTG) has the capability to propagate a laser beam up to 100 m and be able to dial many turbulence settings up to a heat flux of 357 W/m². A high-speed camera, power detector, and high-resolution temperature probes characterize the VTG with theoretical turbulence spectrums. The exponent associated with the Rayleigh-Bénard (RB) temperature structure constant equation is studied. Two different laser beam profiles are used throughout this work: Gaussian and Asymmetric Perfect Vortex (APV). …

Studies Of The Ionosphere-Thermosphere Responses To Multi-Scale Energy Deposition Processes, Haonan Wu

All Dissertations

The Ionosphere-Thermosphere (I-T) system is greatly affected by the magnetospheric energy deposition from above and subjected to forcing from the lower atmosphere simultaneously. A central problem in studying the coupled I-T system is to analyze the multi-scale processes naturally embedded in both ways. Magnetospheric energy input such as auroral precipitation and electric field demonstrates multi-scale structures during magnetic storms, resulting in multi-scale I-T responses when deposited into the I-T system. To better quantify the multi-scale aurora and electric field, we developed a new data assimilation model based on a multi-resolution Gaussian process model to synthesize empirical models and observational data …

Controlled Manipulation Of Droplets On Fibers: Fundamentals And Printing Applications, Yueming Sun

All Dissertations

In this dissertation, the drop interactions with a single fiber is discussed under an application angle for the development on new Drop-on-Demand (DOD) printhead using a fiber-in-a-tube platform[1] to print highly viscous materials[2]. To control the drop formation and manipulation on fiber, one needs to know how the fiber wetting properties and the fiber diameter influence drop formation. And then, one needs to know the effects of fiber movement in the device on drop formation. These two questions constitute the main theme of this dissertation.

Before this study, it was accepted that the liquids could not form axisymmetric droplets if …

Capillary Driven Transport In Soft Solids, Saiful Islam Tamim

All Dissertations

Soft solids, such as polymeric gels, are elastic materials that can be significantly deformed by capillary forces which act at the interface. The coupling between elasticity and capillarity is known as elastocapillarity and is useful to wide ranging applications, from drop pinchoff of bioinks for 3-D printing tissue scaffolds, to generating droplet patterns on microfluidic devices. In this dissertation, we develop mathematical models of elastocapillary driven motions in soft solids. The focus is on understanding the relevant physics in such complex phenomena, while also recovering the limiting cases of classical fluid mechanics and solid mechanics theories.

This dissertation investigates two …