Effects of Wall Catalysis on the Reacting Zone Structure of a Supersonic Flow Chemical Oxygen-Iodine Laser

抄録

The flow field of a supersonic flow chemical oxygen-iodine laser is simulated by solving the three-dimensional full Navier-Stokes equations, and the dependence of the mixing / reacting zone structure and the resulting gain region on the penetration depth of I₂ jet into the primary flow of singlet delta oxygen O₂(¹Δ)is investigated. The effects of wall catalysis are discussed by introducing the surface catalytic efficiency into the wall boundary condition. It is shown that an optimum condition for the secondary I₂ jet momentum exists, and that the jet that causes a high gain penetrates the primary flow up to an intermediate depth and does not collide with the counter one. It is also shown that the molar fractions of I(²P_{1 / 2})and O₂(¹Δ)are reduced markedly on the fully catalytic wall. The deactivated oxygen molecules are engulfed by the vortices generated behind the I₂ jet, leading to the presence of a large amount of unconsumed I₂, the reduced formation of I(²P_{1 / 2})and a large negative gain region in the center of the vortices even far downstream of the nozzle blades. The present study demonstrates the importance of the choice of wall material.