Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Engineering
An Enhanced Operational Definition Of Dielectric Breakdown For Dc Voltage Step-Up Tests, Allen Andersen, Jr Dennison
An Enhanced Operational Definition Of Dielectric Breakdown For Dc Voltage Step-Up Tests, Allen Andersen, Jr Dennison
Journal Articles
The imprecise definition of breakdown in the ASTM D3755-14 standard can misidentify breakdown. If the recommended test circuit current sensing element threshold is set too high, breakdown may occur undetected. Conversely, false positives may result from designating a low current threshold. An operational definition of breakdown much less sensitive to these pitfalls is outlined herein. This enhanced definition of breakdown is based on the average rate of change of the leakage current with increasing voltage, rather than a simple current threshold, avoiding ambiguous association with anomalies in current traces. For tests that continuously monitor leakage current, breakdown can be detected …
Shear Joy Of Watching Paint Dry, Randy Craig Hurd, Nathan B. Spiers, J. Belden, Zhao Pan, B. Lovett, W. G. Robinson, M. A. Zamora, Saberul I. Sharker, Mohammad M. Mansoor, A. Merritt, Tadd T. Truscott
Shear Joy Of Watching Paint Dry, Randy Craig Hurd, Nathan B. Spiers, J. Belden, Zhao Pan, B. Lovett, W. G. Robinson, M. A. Zamora, Saberul I. Sharker, Mohammad M. Mansoor, A. Merritt, Tadd T. Truscott
Mechanical and Aerospace Engineering Faculty Publications
This paper is associated with a video winner of a 2016 APS/DFD Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion.
Three-Dimensional Printing Of "Green" Fuels For Low-Cost Small Spacecraft Propulsion Systems, Stephen A. Whitmore
Three-Dimensional Printing Of "Green" Fuels For Low-Cost Small Spacecraft Propulsion Systems, Stephen A. Whitmore
Mechanical and Aerospace Engineering Faculty Publications
This paper details the advantages of employing modern additive manufacturing methods to fabricate hybrid rocket fuels for intrinsically safe and green small spacecraft propulsion systems. Using additive manufacturing overcomes multiple issues frequently associated with hybrid propulsion, including poor volumetric efficiency, system ignitability, and low fuel regression rates. When certain three-dimensionally printed thermoplastics are subjected to a high-voltage low-wattage charge, electrostatic arcing along the surface pyrolizes a small amount of material that, with the introduction of an oxidizer, “seeds” combustion and produces immediate and reliable ignition. Thermoplastic fuel grains can be printed with port shapes that enhance burn properties and increase …