Abstract
By using a cyclone-jet combustor, we have investigated premixed flames in a highly turbulent flow over a wide range of turbulent properties, with u'/SL exceeding 10 in a stationary jet flame. With Mie scattering, we obtained tomographic images to visualize the flame structure. We have investigated the velocity field in cold flow with a hot wire anemometer. Results show that, as the turbulence is relatively low, the scale of the turbulence is large and one flame sheet wrinkles, which shows that a typical wrinkled laminar flame is formed. As the exit velocity is further increased, the flame wrinkling is increased, but the size of its wrinkles becomes small with many cusps of the flame front. In some cases, the burned gas may exist in the unburned gas, and vice versa. When the velocity exceeds 30 m/s, one continuous flame sheet cannot be sustained, and the destruction of laminar flame structure occurs, in which small reacting eddies in an intermediate stage of combustion may be embedded. These results are supported by the fact in previous experiments that the probability of intermediate temperature between those of unburned and burned gases becomes high and the PDF of temperature is no longer bimodal. Thus, it appears that, a flame structure changes to be that with distributed reaction zone as the intensity of turbulence is increased.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
