Broetz, W.; Schönbucher, Axel; Lucas, R.:

Inferometric synchronous photographs in the study of turbulent processes in tank flames.

In: Berichte der Bunsen-Gesellschaft, Jg. 82 (1978) ; Nr. 2, S. 189-192
ISSN: 0005-9021
Zeitschriftenaufsatz / Fach: Chemie
Abstract:
The partly turbulent flame field of a n-hexane [110-54-3] tank flame, as well as its interaction with the atm. air, is made continuously visible by means of holog. real-time interferometry. In the lower part of the flame between the tank-rim and a flame-height of 80 mm, there is a thick and laminar thermal boundary layer sorrounding the flame. This boundary layer has steep d. temp. gradients perpendicular to the flame axis and parallel to the visible flame outline. Within the tank-flame, the gradient is not very steep, except in a 2nd parabolic boundary layer between the hot flame and the surface of the boiling liq. At the tank-rim, where the sorrounding air flows to the flame front, there are small balls of turbulence, which remain stationary in space. In the central part of the flame, 80-160 mm flame-height, the thermal boundary layer has a macrostructure consisting of large indentations and a microstructure, which could consist of superimposed turbulence-balls. Here, the thermal boundary layer is partly turbulent within the flame and the flame field consists of individual turbulence-balls which are in const. motion, and which dissipate after a certain time. There are also double turbulence-balls in the flame, which are always sorrounded by further turbulence elements in the boundary layer, i.e., outside the visible flame outline.