Master of Science (M.S.), University of Dayton, 2023, Mechanical Engineering

A novel, low cost, high flux solar simulator has been designed and built for the University to be able to undergo research on systems that need testing under high temperature solar irradiation. This simulator will feature four 2500W metal halide bulbs focused with elliptical reflectors, as well as one horizontally translating central 3000W Xenon short-arc lamp with a parabolic reflector and a convex lens acting as a secondary concentrator. To aid in the design, alignment, and characterization of the simulator a detailed Monte Carlo Ray Tracing suite has been developed. These models show that the simulator can produce a flux of 4.5kW/m^2 or around 4500 suns.

Committee: Andrew Schrader Ph.D. (Advisor); Robert Gill (Committee Member); Hagan Evan Bush Ph.D. (Committee Member); Rydge Mulford Ph.D. (Committee Member) Subjects: Engineering; Mechanical Engineering; Systems Design; Technology

Master of Science in Mechanical Engineering (MSME), Wright State University, 2017, Mechanical Engineering

Three-dimensional (3D) printing, a form of Additive manufacturing (AM), is currently being explored to design materials or structures with required Electro-Mechanical-Physical properties. Microstrip patch antennas with a tunable radio-frequency (RF) response are a great candidate for 3D printing process. Due to the nature of extrusion based layered fabrication; the processed parts are of three-layer construction having inherent heterogeneity that affects structural and functional response. The purpose of this study is to identify the relationship between the anisotropy in dielectric properties of AM fabricated acrylonitrile butadiene styrene (ABS) substrates in the RF domain and resonant frequencies of associated patch antennas and also to identify the response of the antenna before and after a low velocity impact. In this study, ANSYS high frequency structure simulator (HFSS) is utilized to analyze RF response of patch antenna and compared with the experimental work. First, a model with dimensions of 50 mm x 50 mm x 5 mm is designed in Solidworks and three separate sets of samples are fabricated at three different machine preset fill densities using an extrusion based 3D printer LulzBot TAZ 5. The actual solid volume fraction of each set of samples is measured using a 3D X-ray computed tomography microscope. The printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the planar properties. The experimental resonant frequency for one fill-density is combined with ANSYS-HFSS simulation results to estimate the bulk dielectric constant of ABS and the equivalent dielectric properties in planar and thickness directions. The bulk dielectric properties are then used in HFSS models for other two fill densities and the simulated results appear to match reasonably well with experimental findings. The similar HFSS modeling scheme was adopted to understand the effect of material heterogeneity on RF response. In (open full item for complete abstract)

Committee: Ahsan Mian Ph.D. (Advisor); Raghavan Srinivasan Ph.D. (Committee Member); Joy Gockel Ph.D. (Committee Member) Subjects: Aerospace Engineering; Automotive Engineering; Design; Electrical Engineering; Mechanical Engineering; Mechanics; Plastics; Technology

Master of Science (MS), Ohio University, 2007, Electrical Engineering & Computer Science (Engineering and Technology)

The purpose of this research was to design a dual feed, dual frequency (i.e., L1L5) patch antenna for the Global Navigation Satellite System (GNSS). First, two commercially available patch antennas were simulated using Ansoft High Frequency Structure Simulator (HFSS) and measured in the Ohio University, School of Electrical Engineering and Computer Science, Antenna Anechoic Chamber. One was a low-cost GPS L1 single frequency patch antenna and other was a GPS L1L2 dual frequency patch antenna. The results from the simulation and measurement for these two antennas are presented, compared, and used as part of the validation process for the dual frequency right hand circularly polarized patch antenna designed for GNSS L1L5 operation. This prototype antenna design was targeted at dual frequency high accuracy civil applications for future GNSS applications. The antenna was designed based on the simulations from HFSS, through which the radiation patterns and other antenna parameters were generated. The predicted performance of this prototype antenna from HFSS simulation generally matches the performance specification for a GNSS dual frequency patch style antenna.

Committee: Chris Bartone (Advisor) Subjects: