4. Flow visualization

V.N. Zudov, P.K. Tretyakov
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Russia, Novosibirsk

Ignition and stabilization by the optical discharge of homogeneous burning in high-speed jet

The experimental research of influence of focused impulsno-periodic radiation СО2 - the laser on initiation and development of process of distribution of burning in to - and a supersonic stream homogeneous fuel-air of mixes (СН4+air) is spent. Radiation СО2-laserа extended across a stream and was focused by a lens on an axis of a supersonic stream. The shadow scheme was applied to registration of structure of a current with a crack and the flat knife located along a stream. The image it was fixed by the high-speed chamber in due course expositions 1.5 µs and frequency of shots 1000 1/s. It is shown, that at cross-section input of laser radiation in a flux the periodic structure of a thermal trace, with a forming of head jump of a gland from a band energy
deposition is formed. At small frequencies of a resulting of pulses of laser radiation interaction of a thermal cloud with a flux occurs in a pulse mode. Is developmental process of non-stationary ignition by the optical category of a metano-air mix is shown at the subsonic expiration in motionless atmosphere. Results of optical visualization testify about burning in a trace behind a field of the optical category.
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