Effect of Tube Size on Flame and Pressure Wave Propagation in a Tube Closed at One End: A Numerical Study (original) (raw)

Experimental investigation of flame and pressure dynamics after spontaneous ignition in tube geometry

International Journal of Hydrogen Energy, 2014

Spontaneous ignition processes due to high pressure hydrogen releases into air are known phenomena. The sudden expansion of pressurized hydrogen into a pipe, filled with ambient air, can lead to a spontaneous ignition with a jet fire. This paper presents results of an experimental investigation of the visible flame propagation and pressure measurements in 4 mm extension tubes of up to 1 m length attached to a bulk vessel by a rupture disc. Transparent glass tubes for visual observation and shock wave pressure sensors are used in this study. The effect of the extension tube length on the development of a stable jet fire after a spontaneous ignition is discussed.

In fl uences of the Initial Ignition Energy on Methane Explosion in a Flame De fl agration Tube

2017

It was observed that the initial ignition energy influences the flame deflagration characteristics of methane explosions. This distinct behavior has been noticed by a number of scholars, and in our laboratory scale explosion chamber recently. However, the flame traveling behavior has not been adequately clarified in industrial scale flame deflagration tube (FDT). This experimental work investigates methane flame deflagration and varied initial ignition in a large scale FDT (30 m long) facilitated at University of Newcastle, Australia, to comprehensively investigate methane flame deflagration behavior. The initial ignition energy was delivered by three alternative chemical ignitors’ energies, which were 1, 5, and 10 kJ. The results of the study revealed the notable influences of the initial ignition energies on the flame deflagrations, over pressure rises, and pressure wave velocities along the FDT. When the initial ignition energy was increased from 1 kJ to 10 kJ, the maximum over p...

Flame deflagration in side-on vented detonation tubes: A large scale study

Journal of hazardous materials, 2018

Venting is often used in process industries to reduce the possibility of dangerous rises in pressure levels and the severity of explosions. To date, the effectiveness of side-on venting on methane flame deflagration in large scale operations has not been clearly addressed. This work explicitly investigates the influences of side-on venting on varied methane flame deflagration concentrations in a 30m long Detonation Tube (DT). corresponding to this study prove the existence of a significant correlation between the fire and explosion driving parameters such as pressure rise and flame propagation velocity with the vent location. It observed venting the explosion at distance between 6.5m and 20.5m from the ignition source resulted in reducing the explosion total pressure by about 33% to 56%. For methane concentration of 7.5% the dynamic and static pressures reduced by about 66% and 33%, respectively. The reduced pressure observed to decelerate the flame velocity by about 70%. Significan...