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Optimization of Spark and ESD Propellant Sensitivity Tests. A review
Author(s) -
Mellor M.,
Stoops David R.,
Rudy Tom P.,
Hermsen Robert W.
Publication year - 1990
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/prep.19900150102
Subject(s) - propellant , spark (programming language) , ignition system , spark gap , parametric statistics , nuclear engineering , sensitivity (control systems) , context (archaeology) , materials science , pyrotechnics , electrode , instrumentation (computer programming) , aerospace engineering , chemistry , engineering , explosive material , computer science , mathematics , electronic engineering , paleontology , statistics , organic chemistry , biology , programming language , operating system
All cured propellants can pass small‐scale spark sensitivity tests, yet some, generally involving larger propellant samples, are electrostatic discharge (ESD) sensitive. These tests fail to rank propellants because the test methods themselves are not optimized and frequently use instrumentation which does not indicate the energy transferred to the sample. For spark ignition of premixed combustible gases or fuel sprays in air, minimum energies are measured and considered thermochemical properties for a given fuel/air ratio, initial temperature and pressure, and for a spray, a given droplet size distribution. Obtaining such data requires monitoring the total energy discharged across the gap during the spark and parametric studies where gap length and spark duration are varied systematically to establish the true minimum (essential to hazard/risk analysis). Electrode geometry and tip design, as well as electrode material, are other important considerations. Present spark and ESD sensitivity tests used for solid propellants are reviewed in the context of methods more likely to provide meaningful initiation thresholds.