Numerical investigation on ignition and flame propagation process of partially covered cavity in a supersonic flow

摘要

In order to study the effect of ignition enhancement of partially covered cavity, ignition and flame propagation process of the partially covered cavity in a scramjet combustor are investigated numerically. Employing the cavity active injection, the characteristics of ignition and flame propagation of three cavity configurations are compared under inflow conditions of Ma = 2.1 with stagnation state P-0 = 0.7 MPa, T-0 = 846 K. It reveals that the cover plate of the cavity is detrimental to flame propagation but beneficial for ignition enhancement. The average static pressure and temperature of the partially covered cavity increases rapidly after ignition and the cover plate works in assembling the fuel in the corner recirculation zone. The covered region will become a fuel-rich region with high pressure and temperature, which acts as an intensified ignition source in the cavity. However, the application of cover plate in the cavity decreases the length-to-depth ratio of the cavity, restricts the flame propagation process and also decreases the thrust generated in the expansion section of the scramjet.