Accession Number : ADA233777


Title :   Laser Initiated Ignition of Liquid Propellant


Descriptive Note : Final technical rept.


Corporate Author : IMPERIAL COLL OF SCIENCE AND TECHNOLOGYLONDON (UNITED KINGDOM)


Personal Author(s) : Carleton, F B ; Krallis, K ; Weinberg, F J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a233777.pdf


Report Date : 31 Jan 1991


Pagination or Media Count : 25


Abstract : As a result of our studies, we conclude that liquid propellant is permanently altered by precursory electrolysis and that focusing outside the drop produces more decomposition. This is attributed to the combined effects of the plasma and shock wave generated during breakdown. It is shown that the NO formed in the air plasma also plays a part. There is little or no difference between the results for Q-switched and free running pulses at the same total energy. Heat treatment followed by varying rest periods has much the same effect as electrolysis. Three propellant mixtures were used for this test: LP-101, HAN/ SBAN and HAN.DEAN. Following previous studies of electrical ignition initiation of liquid propellants in plasma jets by focused laser beams is studied both by fast cine shadowgraphy and by recording permanent gas release as a measure of decomposition. Unlike military propellants, droplets of aqueous mixtures of nitrate salts of hydroxylamine with a 4-carbon aliphatic amine do not ignite when an approx 10 J laser pulse is focused within the liquid. Ignition is achieved by producing breakdown in air in the vicinity of propellant droplets, though little decomposition results, at atmospheric pressure. Precursory electrolysis of varying duration is attempted, in view of postulated chemical mechanisms which suggest that solution of NO in the propellant should enhance ignition. This indeed greatly promotes the vigor of the reaction and leads to an amount of decomposition which increases with increasing time of electrolysis. It appears that the propellant is permanently modified by this simple procedure.


Descriptors :   *SHOCK WAVES , MEASUREMENT , AIR , WATER , PLASMAS(PHYSICS) , LASER BEAMS , GASES , MIXTURES , HEAT TREATMENT , TIME , PROPELLANTS , AMINES , PULSES , CHEMICAL REACTIONS , DROPS , RELEASE , FOCUSING , LIQUID PROPELLANTS , RECORDING SYSTEMS , IGNITION , BAROMETRIC PRESSURE , SALTS , DECOMPOSITION , HYDROXYL RADICALS , REST , PLASMA JETS , NITRATES , ELECTRIC IGNITION , ELECTROLYSIS


Subject Categories : Lasers and Masers
      Combustion and Ignition


Distribution Statement : APPROVED FOR PUBLIC RELEASE