A.A. Smolyakov - Employee, JSC «MSC RF TRINITI» (Troitsk, Moscow). E-mail: smol@triniti.ru A.Yu. Kretinin - Employee, JSC «MSC RF TRINITI» (Troitsk, Moscow) D.Yu. Tkachenko - Employee, JSC «MSC RF TRINITI» (Troitsk, Moscow) M.A. Ogar - Employee, PJSC «NPO Almaz» (Moscow). E-mail: mogar@inbox.ru V.A. Feofilaktov - Ph. D. (Eng.), Senior Research Scientist, PJSC «NPO Almaz» (Moscow)

A characteristic static pressure of active medium in supersonic CO-laser is 50 Torr. Lasers of this type have an optical window for output radiation, which divides the laser medium from outer atmosphere and is closed using a special optical material, or a gas-dynamic valve. A typical flight height of an aircraft with an airborne laser is 10 km. At this height, the atmospheric pressure is sufficiently small (200-230 Torr) to use a laser, in which an optical window for output radiation does not require a special optical material, or a gas-dynamic valve to close it. In practice, it is important to understand the effect of outboard airgetting into the gas-dynamic laser path through the optical resonator window on the gas-dynamic flow characteristics in the gas-discharge chamber and in the resonator region of CO-laser. The paper presents simulation results for the basic gas-dynamic parameters of a steady gas flow in the gas-dynamic path of supersonic CO-laser with regard to an air flow through its optical window. The simulation was performed for optical windows of different structures. Three modified structures of optical window are shown: - air enters directly from atmosphere; - air enters through a «comb»; - «gas window» is used for ground starting. 2D simulations were carried out. The Navier-Stokes equation system was solved. A standard k-e model with the transport equations for kinetic energy of turbulent motion and its dissipation rate equations was used to calculate the turbulent Reynolds stresses.

 

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2. Steven Lamberson. TheAirborneLaser // SPIE. 1996. V. 2702. P. 208.