One-stage free-vortex aerodynamic window with pressure ratio 100 and atmospheric exhaust

Abstract

The aerodynamic windows (AW) are intended for a high power extraction from the gas laser optical cavity, where the pressure is much lower than environment pressure. The main requirements for the aerodynamic windows are to satisfy a low level of optical disturbances in a laser beam extraction channel and an air leakage absence into the optical cavity.Free vortex AW are most economic from a point of working gas consumption and the greatest pressure differential is realized on them at an exhaust to atmosphere. For ideal gas it is possible to receive as much as large pressure differential, however for real gas a pressure differential more than P 5 0 is difficult to achieve.To achieve the pressure ratio 100 in free vortex single-stage AW the method of stabilizing ofboundary layer was used. The gas of curtain was decelerated in the diffuser and was exhausted into the atmosphere straightly. The pressure recovery improvement was achieved by using the boundary layer blowing inside the diffuser. Only 10% of total mass flow was used for boundary layer blowing

A pressure recovery system for chemical oxygen-iodine laser based on an active diffuser

“…In the latter case, the velocity profile in boundary layer becomes filled, the effective boundary layer thickness decreases, and the occurrence probability of separations diminishes. Such a solution was successfully used in implementing a single-stage aerodynamic window designed for a large pressure drop value ε = 100 [11] (aerodynamic windows are used for letting the emission of high-power lasers out; yet, of ordinary single-stage windows values ε = 30 ÷ 40 are typical, and for SCLs two-stage aerodynamic windows, therefore, become necessary). However, in the present case, the high-pressure gas used for blowing in the passive diffuser will induce an additional load for the ejector providing for the exhaust of post-diffuser passive gas into environment.…”

“…The pylons divided the common rectangular channel into several smaller channels (with cross sections of the channels being close to squares); such a channel configuration permitted reduced longitudinal dimensions of the installation. The active section of the active diffuser was formed by a peripheral multi-nozzle bank (3), a small-size constant-cross-section chamber (9), a mixing chamber with constriction (10), an AD throat (11), and a subsonic diffuser (12); in the downstream region of the diffuser, the gas pressure was to reach a value sufficient for normal operation of the second stage of PRS.…”