Abstract. Ammonium perchlorate-aluminum compositions taken in stoichiometric ratio were ignited in air and under the cover with 1.06-µm 0.8-ms-long laser pulses. The ignition energy thresholds were measured for samples at various dispersity of Al. The causes of the difference in examined compositions sensitivity to the influence of laser radiation is considered from the perspective of the thermal theory.

Laser ignition of stoichiometric mixture based on aluminum nanopowder and ammonium perchlorate were studied experimentally. The laser with a radiation wavelength of 1.06 μm and a pulse duration of 0.8 ms was used as a source of heat. The ignition thresholds were determined for open samples in the air and for samples confined with transparent dielectric. The difference in the obtained data is discussed within the thermal ignition theory.

The experimental investigations of laser‐induced ignition and heat action of ammonium perchlorate and aluminum powder mixtures are presented in this paper. A laser pulse with wavelength of 1.06 μm and duration of 3.5 ms was used. Powder mixtures of different dispersion were tested, namely, coarsely dispersed powders and nanopowders with average surface diameters of 80 and 0.25 μm, respectively. The values of ignition thresholds and delays of the mixtures activity in air were measured, and experimental results for different exposure conditions were obtained. The possible reasons of different sensitivity for the given mixtures to laser pulse and heat action are discussed.

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Abstract. Currently mist water is one of the most promising areas of fire protection. We performed an experimental study of phase transformations drops of water mist (range 50 -500 microns) in motion in a high-temperature (500 -2000 K) typical products of combustion of petroleum products (gasoline, kerosene, acetone, alcohol). We used high speed (the speed of shooting at least 10 5 frames per second) and optical methods of recording streams of liquid and gas medium. We determined the effect of the parameters of the test process (the initial temperature and the initial droplet size) at the rate of evaporation of atomized water under these conditions.