A photographic investigation of the collision, reaction, and ignition of hypergol droplets

Abstract

The experimental apparatus employed in this investigation permitted a fuel droplet and an oxidizer droplet to collide in a nitrogen atmosphere at temperatures from 50°C to 430°C. The resulting phenomena were photographed with a 16mm Fastax camera.

Experimentation was completed in three series of tests. The first series consisted of impacting hydrazine droplets with white fuming nitric acid droplets at an impact velocity of 35 cm/sec and at temperatures from 200°C to 425°C. The second series utilized the same fuel and oxidizer at an impact velocity of 122 cm/sec and at temperatures ranging from 50°C to 430°C. The third series employed an alcohol-aniline mixture as the fuel droplets, and white fuming nitric acid as the oxidizer droplets. The impact velocity was 35 cm/sec and the nitrogen temperature ranged from 50°C to 415°C.

Ignition was not obtained in the two series employing hydrazine as a fuel. The droplets, upon colliding, underwent a chemical reaction and were blown apart. With the series utilizing an alcohol-aniline mixture as the fuel, the droplets, after collision, formed one large drop which vaporized rapidly. The vapors ignited with flame at temperatures over 200°C.