Studies on Hypergolicity of Several Liquid Fuels with fuming nitric acids as oxidizers

Abstract

AbstractHypergolic or self ignition delays of unsymmetrical dimethylhydrazine (UDMH) and several amine fuels, mixed with three fuming nitric acid oxidizers, have been determined, at room temperature, in a highly sensitive “Cup Test” apparatus. Ignition delay (ID) variations have been studied with respect to the chemical structure of fuel, oxidizer composition, and oxidizer‐to‐fuel (O/F) ratio. Probable preignition reactions and structure‐hypergolicity correlations have been suggested.Some non‐hypergolic hydrocarbons and petroleum fractions have been hypergolized by addition of UDMH, and ID variations have been studied with respect to UDMH‐content in fuel and catalytic additives (ammonium metavanadate, ammonium dichromate, and cuprous oxide) in the red fuming nitric acid oxidizer (RFNA). Increment in UDMH‐content improves the hypergolicity of fuels towards RFNA. For example, kerosene + UDMH 60:40 blend ignites with RFNA with a remarkably low ID of 6 ms. However, the catalytic effect of the additive in RFNA varies widely with the fuel‐blend composition.