Other Aerospace Engineering Commons^™

Characterization Of The Spallation Phenomenon In Ablative Thermal Protection System Materials Resulting From Arc-Jet Experiments, Kristen Price

Theses and Dissertations--Mechanical and Aerospace Engineering

Thermal protection systems are critical for protecting spacecraft from the large amounts of heating incurred during atmospheric entry. Ablative thermal protection systems in particular often consist of a carbon fiber matrix impregnated with a polymer resin and use thermal and chemical reactions to decompose the material. Weakening of these carbon fibers by oxidation, along with the impact of shear forces, results in the mechanical failure of these materials in a process known as spallation. Being able to quantify and characterize this process is important for modeling and designing heat shield materials that account for the additional spalled mass loss.

Two …

Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha

Theses and Dissertations--Mechanical and Aerospace Engineering

The objective of this research is to improve precision meteorological prediction, benefiting both uncrewed aerial vehicle (UAV) operations by avoiding hazardous flight conditions and tracking contaminant or toxic clouds caused by incidents, accidents, or fires. The operational concept is to collect meteorological observations from instruments mounted on a swarm of UAVs, telemeter the data to a weather simulation model, revise the predicted solution by adapting the flow field to the observations, and then transmit the updated forecast to appropriate personnel as well as to the guidance system of UAVs for repositioning to the next set of most beneficial measurements. While …

Enhanced Surface Integrity With Thermally Stable Residual Stress Fields And Nanostructures In Cryogenic Processing Of Titanium Alloy Ti-6al-4v, James R. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

Burnishing is a chipless finishing process used to improve surface integrity by severe plastic deformation (SPD) of surface asperities. As surface integrity in large measure defines the functional performance and fatigue life of aerospace alloys, burnishing is thus a means of increasing the fatigue life of critical components, such as turbine and compressor blades in gas turbine engines. Therefore, the primary objective of this dissertation is to characterize the burnishing-induced surface integrity of Ti-6Al-4V alloy in terms of the implemented processing parameters. As the impact of cooling mechanisms on surface integrity from SPD processing is largely unexplored, a particular emphasis …