A Reduced Order Model For Efficient Physiological Flow Analysis In Aneurysms By Proper Orthogonal Decomposition, 2016 University of Massachusetts Amherst
A Reduced Order Model For Efficient Physiological Flow Analysis In Aneurysms By Proper Orthogonal Decomposition, Gary Han Chang, Yahya Modarres-Sadeghi
UMass Center for Clinical and Translational Science Research Retreat
Simulating physiological flows using computational fluid dynamics (CFD) remains to be computationally expensive and difficult for clinical usage because of the physiological flow and geometrical complexity involved in patient specific situations. We use the reduced order modeling (ROM) of such systems with high nonlinearity and geometrical non-uniformity to replace the full, nonlinear model with a low-degrees of freedom ROM model. We construct ROM models by the proper orthogonal decomposition (POD) method to estimate the flow-induced wall shear stress (WSS) and pressure loading of a simplified abdominal aortic aneurysm and a bifurcation cerebral aneurysm. This method allows us to investigate a ...
Detection Of Acoustic Sources Using Time-Reversal Methods, 2016 The University of Southern Mississippi
Detection Of Acoustic Sources Using Time-Reversal Methods, Grant E. Tingstrom
The goal of this research is to characterize the impact of using an equivalent-fluid method for a solid seabed on the use of time reversal procedures for detecting the origin location of an emitted sound. There are two different ways of modeling how sound propagates through water: modeling sound as a ray and modeling sound as a wave. It is easier to model the propagation of sound through water with a ray model; using a ray model allows for the collection of grazing angles with respect to the bottom. These will be important when determining bottom intensity loss of the ...
Momentum Transfer To A Simplified Wind Turbine Blade, 2016 The University of Southern Mississippi
Momentum Transfer To A Simplified Wind Turbine Blade, Myer D. Milbrath
This project looks into the potential of simplified simulations as a supplement to wind turbine blade designs. The idea is to take a two-dimensional representation of a wind turbine blade and attempt to use a fluid flow simulation to determine which "aspect ratio" is the most efficient in the transfer of momentum. This is then compared to the current requirements for wind turbine blades to judge how accurate the simulation was. It was found that an aspect ratio of 16.66 percent was most efficient, however when compared to the requirements for a wind turbine blade this ratio only falls ...
Improving Ventricular Catheter Design Through Computational Fluid Dynamics, 2016 University of Tennessee - Knoxville
Improving Ventricular Catheter Design Through Computational Fluid Dynamics, Sofy Hefets Weisenberg
Cerebrospinal fluid (CSF) shunts are fully implantable medical devices that are used to treat patients suffering from conditions characterized by elevated intracranial pressure, such as hydrocephalus. In cases of shunt failure or malfunction, patients are often required to endure one or more revision surgeries to replace all or part of the shunt. One of the primary causes of CSF shunt failure is obstruction of the ventricular catheter, a component of the shunt system implanted directly into the brain's ventricular system. This work aims to improve the design of ventricular catheters in order to reduce the incidence of catheter obstruction ...
Particle Image Velocimetry Design & Installation, 2016 University of Arkansas, Fayetteville
Particle Image Velocimetry Design & Installation, Zach Ritchie
Mechanical Engineering Undergraduate Honors Theses
This work will mainly focus on the design, construction, and installation of the Particle Image Velocimetry (PIV) system in the Chemical Hazards Research Center wind tunnel. The PIV system utilizes a Class IV (double pulsed) laser, optics to produce a light sheet, timing circuitry, and a high-resolution camera (with buffered output) to measure a system’s velocity (two-dimensional) field by determining the displacement of particles over the time between laser pulses. For maximum mobility and functionality, the PIV system was installed in the center of the tunnel on a moveable cart with the laser and camera mounted to an adjustable ...
Pulsed-Laser Induced Dewetting Of Metallic Nanostructures, 2016 University of Tennessee - Knoxville
Pulsed-Laser Induced Dewetting Of Metallic Nanostructures, Christopher Aidan Hartnett
This dissertation explores the fluid dynamics of nano and microscale liquid metal filaments, with an emphasis on experimentally investigating the influences and causes of filament breakup and metallic nanostructure formation. Understanding and manipulating the liquid state properties of materials, especially metals, have the potential to advance the development of future technology, particularly nanoscale technology. The combination of top-down nanofabrication techniques with bottom-up, intrinsic self-assembly mechanisms are a powerful fusion, because it permits new and unusual nanostructures to be created, whilst revealing interesting nanoscale physics.
In fluid dynamics, wetting and dewetting is the spontaneous natural process that occurs when a liquid ...
Procesy Cieplne I Aparaty (Lab), 2016 Wroclaw University of Technology
Procesy Cieplne I Aparaty (Lab), Wojciech Budzianowski
An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, 2016 Michigan Technological University
An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur
Dissertations, Master's Theses and Master's Reports
Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic ...
Active 2d Microrheological Studies In Freely-Suspended Smectic Liquid Crystal Films, 2016 University of Colorado Boulder
Active 2d Microrheological Studies In Freely-Suspended Smectic Liquid Crystal Films, Kyle R. Ferguson
Undergraduate Honors Theses
Thin, freely-suspended smectic liquid crystal films, due to their layered structure, provide an ideal system with which to study two dimensional (2D) hydrodynamics. We have performed some of the first experimental visualizations of actively-driven 2D flow fields, and compared these flow fields to predictions made by theoretical models. First, an experiment testing the flow field generated by a disk-shaped inclusion moving laterally in a film is described. Then an experiment testing the flow field generated by a thin nozzle injecting fluid at a quick rate into a large reservoir is detailed. Results are consistent with the idea that 2D fluids ...
Complex Capillary Fluidic Phenomena For Passive Control Of Liquids In Low-Gravity Environments, 2016 Portland State University
Complex Capillary Fluidic Phenomena For Passive Control Of Liquids In Low-Gravity Environments, Logan Torres
Undergraduate Research & Mentoring Program
In an effort to further apply the recent results of puddle jumping research, we seek to expand the oblique droplet impact studies of others by exploiting large liquid droplets in the near weightless environment of a drop tower. By using the spontaneous puddle jump mechanism, droplets of volumes 1 mL ≤ V ≤ 3 mL with corresponding Weber numbers of We ≈ 1 are impinged on surfaces inclined in the range 40° ≤ α ≤ 80° (measured from the horizontal plane). Impact surface wetting characteristics exhibit static contact angles θstatic = 165 ± 5°. All impacts result in complete rebound. At surface inclinations α > 70° and droplet ...
Perspectives For Low-Carbon Electricity Production Until 2030: Lessons Learned From The Comparison Of Local Contexts In Poland And Portugal, 2015 Wroclaw University of Technology
Perspectives For Low-Carbon Electricity Production Until 2030: Lessons Learned From The Comparison Of Local Contexts In Poland And Portugal, Wojciech Budzianowski, Joao Gomes
This paper compares perspectives for low-carbon electricity production in two EU member states - Poland and Portugal until 2030. Electricity production capacities, carbon emissions of electricity production, and production cost of electricity (COE) of Poland and Portugal are analyzed. The dilemmas of investments into low-carbon electricity production technologies relying on: (i) renewable energy sources (RES), (ii) nuclear fuel, and (iii) fossil fuels integrated with carbon capture and sequestration (CCS) are discussed. Roadmap 2050 recommends about 40% decarbonization of electricity generation by 2030 and 100% by 2050. Based on electricity production mix forecast for 2030 carbon emissions of electricity are estimated at ...
Inżynieria Chemiczna Lab., 2015 Wroclaw University of Technology
Inżynieria Chemiczna Lab., Wojciech Budzianowski
Order Form Resrb 2017, 2015 Wroclaw University of Technology
Order Form Resrb 2017, Wojciech M. Budzianowski
No abstract provided.
Renewable Energy And Sustainable Development (Resd) Group, 2015 Wroclaw University of Technology
Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski
No abstract provided.
Conference Proceedings, Resrb 2016, June 22-24, 2016, Wrocław, Poland, 2015 Wroclaw University of Technology
Conference Proceedings, Resrb 2016, June 22-24, 2016, Wrocław, Poland, Wojciech M. Budzianowski
No abstract provided.
A1, 2015 Wroclaw University of Technology
A1, Wojciech M. Budzianowski
No abstract provided.
Abstract Template Resrb 2017, 2015 Wroclaw University of Technology
Abstract Template Resrb 2017, Wojciech M. Budzianowski
No abstract provided.
Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, 2015 University of New Orleans
Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, John B. Potts Iii
University of New Orleans Theses and Dissertations
An anguilliform swimming robot replicating an idealized motion is a complex marine vehicle necessitating both a theoretical and experimental analysis to completely understand its propulsion characteristics. The ideal anguilliform motion within is theorized to produce ``wakeless'' swimming (Vorus, 2011), a reactive swimming technique that produces thrust by accelerations of the added mass in the vicinity of the body. The net circulation for the unsteady motion is theorized to be eliminated.
The robot was designed to replicate the desired, theoretical motion by applying control theory methods. Independent joint control was used due to hardware limitations. The fluid velocity vectors in the ...
Effect Of Slow Compression On The Linear Stability Of An Accelerated Shear Layer, 2015 Portland State University
Effect Of Slow Compression On The Linear Stability Of An Accelerated Shear Layer, John Ramshaw
John D. Ramshaw
An analysis is given of the effect of a slow uniform anisotropic compression or expansion on the linear stability of a normally accelerated planar interface between two fluids with different densities and tangential velocities, i.e., a combined Kelvin-Helmholtz and Rayleigh-Taylor instability, but generalized to an arbitrary time-dependent acceleration history. The compression is presumed to be sufficiently slow that the density remains uniform within each fluid and hence depends only on time. The perturbation is taken to be sinusoidal with amplitude h(t). The time evolution of h is determined by requiring pressure continuity across the interface in the usual ...
Partial Chemical Equilibrium In Fluid Dynamics, 2015 Portland State University
Partial Chemical Equilibrium In Fluid Dynamics, John Ramshaw
John D. Ramshaw
An analysis is given for the flow of a multicomponent fluid in which an arbitrary number of chemical reactions may occur, some of which are in equilibrium while the others proceed kinetically. The primitive equations describing this situation are inconvenient to use because the progress rates ω [subscript s] for the equilibrium reactions are determined implicitly by the associated equilibrium constraint conditions. Two alternative equivalent equation systems that are more pleasant to deal with are derived. In the first system, the ω [subscript s] are eliminated by replacing the transport equations for the chemical species involved in the equilibrium reactions ...