ИСТИНА

Lean spherical hydrogen–air flames at 4 orders of magnitude in size and energy Elyanov A E, Golub V V, Mikushkin A Yu@, Petukhov V A and Volodin V V Joint Institute for High Temperatures of the Russian Academy of Sciences, Izhorskaya 13 Bldg 2, Moscow 125412, Russia @ notna17@yandex.ru Free spherical premixed flames propagation is studying in volumes of cubic centimeters to hundreds of cubic meters. Ignition energies range from parts of a millijoule to tens of kilojoules. Typically, the authors compare the results with similar scale data. Experimental studies of flame propagation in a wide range of scales are not available in scientific literature. The subjects of the present work are identification of features of common and different for the flame propagation in volumes from 4 liters to 40 cubic meters; comparison of the flame propagation modes upon ignition with energies from 1 mJ to 5 J; explanation of differences in results when using different shells that limit the volume of the combustible mixture. A series of experiments on spherical propagation of flame front in various shells is conducted. The position and morphology of the flame front was recorded with infrared camera Infratec ImageIR 8320 with spectral range 2–5.7 μm and schlieren device IAB-451 equipped with high-speed camera Videosprint G2. Dependences of the flame front position versus time are obtained. The study is supported by the Russian Science Foundation (grant No. 14-50-00124). Large scale experiments were conducted using the equipment of the Moscow Regional Explosive Center for Collective Use RAS.