Velocity and temperature measurements in a vertical wall flame

Journal of Physics: Conference Series

Andres Valencia^1¹  Bertrand Lecordier^2² 

[1]Department of Fire Protection Engineering, University of Maryland, USA^1

[2]UMR 6614 CORIA, INSA Rouen, France^2

DOI  :  10.1088/1742-6596/1107/3/032006

学科分类：物理（综合）

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

To study the combustion of vertical solids, a laboratory setup has been built in order to produce stationary and easily repeatable experiments. It consists of a rectangular porous burner fed with a mixture of methane and ethylene, which produces a sooting and luminous flame. That system has been already used to determine the soot concentration in a vertical flame [1,2]. Velocity and temperature measurements were performed inside the reactive boundary layer. The average velocities (horizontal and vertical), as well as their fluctuations, were measured thanks to the 'Particle Image Velocimetry' laser diagnostic. Temperature profiles were obtained using fine thermocouples placed at different heights. The visual appearance of the flame shows that it is fully turbulent from a height of about 20cm. In this turbulent zone of the flame, the profiles of the vertical velocity and the temperature evolve similarly according to the height. Near the wall, the velocity and the temperature increase rapidly and reach a maximum located a few millimeters to the wall. For the velocity, this maximum increases with the height in the flame because of the entrainment of the hot gases by the effects of gravity. For the temperature, such evolution of the maximum is not observed. Far away the wall, the velocity and temperature profiles widen toward the outside of the boundary layer, because of the dilution with the air. On the other hand, the horizontal velocity fluctuations are high compared to the mean values and at each height the profiles have a maximum which is more shifted from the wall. A heat flux sensor was placed just above the burner to determine the total heat flux received. The mean value is 23.6 kW / m2. The latter value will be analyzed and compared, as well to the velocity and temperature measurements, to other values obtained for the same wall flame configuration [3-5].

【 授权许可】

Unknown