Effect of copper foam location on syngas-air explosion in a closed duct

Abstract

Experiments were conducted in a closed duct filled with copper foam to study the premixed syngas-air flame propagation behaviors. A copper foam with a thickness of 20 mm is installed at different distance from the ignition end (CFLs) respectively. The stoichiometric syngas-air with different hydrogen volume fractions in syngas (α(H2)s) is employed. Results show that the setting of copper foam does not affect the flame evolution process before the flame tip reaches the copper foam. The flame shape observed when the flame tip reaches the copper foam is closely related to the distance between the copper foam and igniter. The presence of copper foam can contribute to aggravate the chaos of the flame front. In most cases, the flame accelerates after passes through the copper foam only except for α(H2) = 10%, along with rise and oscillation of the flame velocity and overpressure. The flame acceleration is enhanced with the increase of α(H2) but decrease of CFL. In general, the copper foam may be more dangerous when it is closer to the ignition end and the α(H2) is high.