Premixed Hydrogen/air Flame in Ceramic Granular Bed

This study investigates the characteristics of a lean premixed hydrogen/air flame in a ceramic granular bed (CGB) by conducting experimental measurements and numerical simulations. The experimental results show that the operating range (equivalence ratio, phi=0.2-0.4) of CGBs for flame propagation is smaller than that of free flame due to the laminar flame speed (S-L), reactivity, and firing rate (Gamma) of H-2. In addition, flame temperature (T-f) increases with increasing, but decreases with increasing phi. Furthermore, S-ab/S-L decreases with increasing u(epsilon)/S-L by the fuel characteristic of Hydrogen (H-2) and heat recirculation in the CGB. The numerical simulation results show that the flame reaction zone in the CGB (porosity, epsilon = 0.33) is greater than that of free flame (epsilon = 1) because H2 reacts early and changes the flame propagation characteristics. (C) 2015 Published by Elsevier Ltd.