Mechanical Engineering Commons^™

Optimization Of Titanium Liquid/Gas Diffusion Layers In Proton Exchange Membrane Electrolyzer Cells, Stuart Mccoy Steen

Masters Theses

Polymer electrolyte membrane electrolyzer cells (PEMECs), which are reverse PEM fuel cells (PEMFCs), are effective energy storage medium by producing hydrogen/oxygen from water using electricity from renewable energy sources. This is due in part because of its efficiency, high energy density, compact design, and large capacity. In a PEMEC, a liquid/gas diffusion layer (LGDL) is located between the catalyst layer and the current distributing flow field. The LGDL is expected to transport electrons, heat, and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic losses. Carbon materials (carbon paper or carbon cloth), typically used …

Measurements Of Methyl Radicals And Temperatures By Using Coherent Microwave Rayleigh Scattering From Resonance Enhanced Multiphoton Ionization, Yue Wu

Doctoral Dissertations

This thesis includes two main parts: (I) The CH₃[methyl radical] detection in methane/air flames and (II) the rotational temperature measurement of O₂[molecular oxygen] in a variety of environments by using coherent microwave Rayleigh scattering from resonance enhanced multiphoton ionization (Radar REMPI).

In first the part, from Chapter I to Chapter III, the methyl radical detection and quantitative measurements have been conducted in hydrocarbon flame with one-dimensional and two-dimensional spatial-resolved concentration distribution. Due to the proximity of the argon resonance state (4+1 REMPI by 332.5 nm) with the CH₃ state (2+1 REMPI by 333.6 nm), in …

Cfd Analysis Of Viscosity Effects On Turbine Flow Meter Performance And Calibration, Carl Tegtmeier

Masters Theses

In this research turbine flow meters were studied, using computational fluid dynamics (CFD) modeling to the study effects of viscosity on the flow meters, across a wide range of operation, to improve our understanding and their performance. A three-dimensional computational model was created for a typical flow meter geometry. The work began with a steady state model to provide an acceptable initial condition for further simulations. These results were input into a transient model that has a rotating zone around the rotor to provide insight into the interaction between static and rotational structures. In order to automatically adjust the rotor …