Barrett, The Honors College Thesis/Creative Project Collection
Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.
Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.
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Description
The temperature of exhaust pipes can be dangerous in dry areas where there is a lot of brush. The temperatures of exhaust pipes can reach a high enough temperature to start a fire if touching the dry brush, which ignites around 300°C. The goal of this project was to explore different techniques to limit the possibility of these brush fires. Specifically, different methods were explored to reduce the temperature of the pipe that would be contacting the brush. Fires can begin within seconds of contacting the hot exhaust pipes [10]. This experiment found that of the three options tested: exhaust wrap, heat sink with thermoelectric devices, and high temperature paint, adding a heat shield/sink is the best way to limit the high temperatures from igniting the brush. There was a cooling difference of nearly 100°C when a heat shield/sink was added to the bare pipe. The additional thermal mass as well as the finned heat sinks attached to the heat sink helped dissipate the heat from the pipe and release the waste heat into the surroundings. The increase in surface area in correspondence with forced convection from the surrounding air lowered the temperature of the metal in contact with the dry brush.
ContributorsHodges, Andrew (Author) / Benson, David (Thesis director) / Bocanegra, Luis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Smallsats such as CubeSats have a variety of growing applications in low Earth orbit (LEO), near Earth orbit (NEO), and deep space environments across communications, imaging, and more. Such applications have tight pointing requirements and thus an accompanying need for attitude control systems (ACS) with finer pointing capabilities and longer lifetimes. Current systems such as magnetorquers and reaction wheels have notable limitations. Magnetorquers lose applicability for many deep space applications while the latter is dependent on moving components and cannot be operated independently due to momentum saturation among other limitations. Micro-Pulsed Plasma Thrusters (μPPTs) can be designed for multi-axis control in space. The use of solid Teflon (PTFE) propellant to produce a controllably small impulse within the thrusters can enable increased fine pointing accuracy and precision. In this paper, a preliminary design of an 8-thruster set of breech-fed μPPTs is analyzed through mechanical simulation tools to address challenges posed by miniaturization into a 1U module. Mechanical challenges of miniaturizing a μPPT module are particularly driven by the volume constraint and the associated appropriate mass. Thermal analysis performed using C&R Thermal Desktop, addresses the thermal environment for various use cases, individual component heating, as well as heat transfer through the module. This directly informs component layout recommendations and thermal controls based upon maintaining operational temperature ranges for various use cases. This model as well as fabrication considerations inform material selections for various structures in the preliminary μPPT design. In this paper I will discuss the overall design of the PPT model that has been configured here at Arizona State University by the Sun Devil Satellite Laboratory. I will then discuss the findings of my thermal analysis that was performed using Thermal Desktop.
ContributorsArnest, Dylan (Author) / Benson, David (Thesis director) / Acuna, Antonio (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05