- Author
-
Lee, J. H.
|
Knystautas, R.
|
Chan, C. K.
- Title
- Turbulent Flame Propagation in Obstacle-Filled Tubes.
- Coporate
- McGill Univ., Montreal, Canada
- Book or Conf
- Combustion Institute, Sympoisum (International) on Combustion, 20th. August 12-17, 1984,
Combustion Institute, Pittsburgh, PA,
Michigan Univ., Ann Arbor,
1663-1672 p.,
1985
- Keywords
-
flame propagation
- Abstract
- Turbulent flame acceleration experiments have been carried out in steel tubes of 5 cm, 15 cm and 30 cm diameter and ranging from 11 to 17 m in length. Circular orifice plates spaced one diameter apart were used as flow obstructions. The blockage ratios BR = 1 -(d/D)2 are 0.44, 0.39 and 0.28 corresponding to orifice diameters of 3.74 cm, 11.7 cm and 25.8 cm for the 5 cm, 15 cm and 30 cm diameter tubes, respectively. Mixtures of hydrogen, acetylene, ethylene, propane and methane with air were used over a range of fuel compositions. The results indicate the existence of four propagation regimes: the quenching, the choking, the quasi-detonation and the C-J detonation regimes. In the quenching regime, the flame is first found to accelerate and then extinguish itself after propagating past a certain number of orifice plates. The flame propagation process in the quenching regime can be considered as the successive ignition of a sequence of chamber separated by the orifice plates.Ignition in one chamber is due to the venting of the hot combustion products from the upstream chamber through the orifice. Quenching occurs when the jet fails to ignite the mixture due to too short a mixing time when compared to the chemical reaction time.