EFFECTS OF WALL CATALYSIS ON THE REACTING ZONE STRUCTURE OF A SUPERSONIC-FLOW CHEMICAL OXYGEN-IODINE LASER

The flow field of a supersonic how chemical oxygen-iodine laser is sim ulated by solving the three-dimensional full Navier-Stokes equations, and the dependence of the mixing/reacting zone structure and the resul ting gain region on the penetration depth of I-2 jet into the primary flow of singlet: delta oxygen O-2((1)Delta) is investigated. The effec ts of wall catalysis are discussed by introducing the surface catalyti c efficiency into the wall boundary condition. It is shown that an opt imum condition for the secondary It jet momentum exists, and that the jet that causes a high gain penetrates the primary flow up to an inter mediate depth and does not collide with the counter one. It is also sh own that the molar fractions of I(P-2(1/2)) and O-2((1)Delta) are redu ced markedly on the fully catalytic wall. The deactivated oxygen molec ules are engulfed by the vortices generated behind the I-2 jet, leadin g to the presence of a large amount of unconsumed It, the reduced form ation of I(P-2(1/2)) and a large negative gain region in the center of the vortices even far downstream of the nozzle blades. The present st udy demonstrates the importance of the choice of wall material.