Mechanical Engineering Commons^™

Simulating The Effects Of Floating Platforms, Tilted Rotors, And Breaking Waves For Offshore Wind Turbines, Hannah Johlas

Doctoral Dissertations

Offshore wind energy is a rapidly expanding source of renewable energy worldwide, but many aspects of offshore wind turbine behavior are still poorly understood and are not accurately captured by low-cost engineering models used in the design process. To help improve these models, computational fluid dynamics (CFD) can provide valuable insight into the complex fluid flows that affect offshore wind turbine power generation and structural loads. This research uses CFD simulations to examine three main topics important to future offshore wind development: how breaking waves affect structural loads for fixed-bottom wind turbines; how platform motions affect power generation, wake characteristics, …

Numerical Modeling Of Advanced Propulsion Systems, Peetak P. Mitra

Doctoral Dissertations

Numerical modeling of advanced propulsion systems such as the Internal Combustion Engine (ICE) is of great interest to the community due to the magnitude of compute/algorithmic challenges. Fuel spray atomization, which determines the rate of fuel-air mixing, is a critical limiting process for the phenomena of combustion within ICEs. Fuel spray atomization has proven to be a formidable challenge for the state-of-the-art numerical models due to its highly transient, multi-scale, and multi-phase nature. Current models for primary atomization employ a high degree of empiricism in the form of model constants. This level of empiricism often reduces the art of predictive …

Novel Piezo Actuators For Surface Cleaning, Yezad H. Anklesaria

Doctoral Dissertations

"Optical cameras are becoming increasingly common and are used in a variety of applications. With recent progress and transition toward more autonomous systems, the usage of optical systems will be common and widespread. Applications of the optical systems range from autonomous vehicles, home security systems, aviation, extraterrestrial vehicles, spacecraft, and satellites. Imaging systems are used in decision-making in many of these applications. Fouling of the field of view of the imaging system can impede the decision process. An active autonomous cleaning method for the optical surface of the optical systems reliably would be advantageous. The research work focuses on developing …

Theoretical Study Of Magnetic Particles In A Shear Flow Subjected To A Uniform Magnetic Field, Christopher A. Sobecki

Doctoral Dissertations

"Magnetic manipulation of non-spherical magnetic microparticles is important for applications in shape-based and magnetic-based separations such as waste management, disease diagnostics, drug delivery, and mining. Manipulations of magnetic microparticles also include chain formation to assemble compositions for electronics, drug loading designs, and magnetorheological fluids for smart armor, hydraulic brakes, and dampers. In microfluidic devices, separation-formation-effectiveness depends on the shape of the channel, the shear rate, and the magnetic field strength and direction.

Particle separation and chain formation involved highly complex and computational expense-demanding studies in microfluidic devices, magnetic fields, and particle- particle/wall interactions. This research took complex experimental studies and …

Dynamic Behavior And Interactions Of Ferrofluid Droplets Under Magnetic Fields In Low Reynolds Number Flows, Md Rifat Hassan

Doctoral Dissertations

Digital microfluidics in combination with emulsion microfluidics are crucial building blocks of droplet-based microfluidics, which are prevalent in a wide variety of industrial and biomedical applications, including polymer processing, food production, drug delivery, inkjet printing, and cell-based assays. Therefore, understanding the dynamics and interactions of droplets as well as the interactions between the droplets and solid surfaces are of great importance in order to improve the performance or product in these applications.

Recently, several studies in the literature have demonstrated the potential of magnetic fields in controlling the behavior of droplets in microscale; however, the fundamental mechanism behind the interesting …