Infrared Thermographic Study of Laser Ignition

Conference · Tue Jul 01 04:00:00 EDT 1986

OSTI ID:970956

Mohler, Jonathan H; Chow, Charles T. S.

Pyrotechnic ignition has been studied in the past by making a limited number of discrete temperature-time observations during ignition. Present-day infrared scanning techniques make it possible to record thermal profiles, during ignition, with high spacial and temporal resolution. Data thus obtained can be used with existing theory to characterize pyrotechnic materials and to develop more precise kinetic models of the ignition process. Ignition has been studied theoretically and experimentally using various thermal methods. It has been shown that the whole process can, ideally, be divided into two stages. In the first stage, the sample pellet behaves like an inert body heated by an external heat source. The second stage is governed by the chemical reaction in the heated volume produced during the first stage. High speed thermographic recording of the temperature distribution in the test sample during laser ignition makes it possible to calculate the heat content at any instant. Thus, one can actually observe laser heating and the onset of self-sustained combustion in the pellet. The experimental apparatus used to make these observations is described. The temperature distributions recorded are shown to be in good agreement with those predicted by heat transfer theory. Heat content values calculated from the observed temperature distributions are used to calculate thermal and kinetic parameters for several samples. These values are found to be in reasonable agreement with theory.

• Research Organization: MOUND (Mound Plant, Miamisburg, OH (United States)); Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-76DP00053
• OSTI ID: 970956
• Report Number(s): MLM-3377(OP)
• Country of Publication: United States
• Language: English