Premixed Syngas Flame Propagation in an Enclosed Constant Volume Chamber

摘要

This work presents a numerical investigation of two-dimensional, premixed syngas flame propagation in a rectangular channel having aspect ratio ten (10). The hydrogen mass fraction values are 0.2, 0.5 and 0.8 and the equivalence ratio for each case takes the values 0.7, 1.0, and 1.5. The confined mixture, initially at rest, has temperature 300 K and pressure 1 atm. The channel walls are isothermal (300 K) to incorporate the influence of heat losses from the walls. The simulations are conducted using a recently developed detailed kinetic mechanism of 48 chemical reactions between fifteen (15) species. The mixture-averaged transport model has been adopted and the Soret effect was included. The results indicate that the equivalence ratio and hydrogen content in the syngas fuel produce a significant influence on flame structure, pressure-time history, and flame propagation under constant volume combustion conditions. The acceleration in flame speed due to the increase in hydrogen content depends strongly and nonlinearly on the equivalence ratio. The flame front shows a greater wrinkling structure for a equivalence ratio of 0.7 compared with 1.0 and 1.5. The flame front becomes less wrinkled near the channel end wall (after 8.5 cm).