High-performance chemical oxygen-iodine laser using nitrogen diluent for commercial applications

A chemical oxygen-iodine laser (COIL), the VertiCOIL device, was transferre d from the Air Force Research Laboratory (AFRL) to the University of Illino is at Urbana-Champaign (UIUC) and made operational. The performance of the high-power VertiCOIL, laser was measured with nitrogen diluent. New nozzle designs were investigated and implemented to optimize nitrogen performance. Nitrogen diluent chemical efficiencies of a 23% mere achieved; these are t he highest reported chemical efficiencies with room-temperature nitrogen di luent, A long duration, high chemical efficiency test was demonstrated with nitrogen diluent; a chemical efficiency of 18.5% at 30 mmol/s of chlorine Um was maintained for 45 min. The highest performance was obtained with new iodine injector blocks and a larger throat height. The new iodine injector blocks moved the injectors closer to the throat by 0.7 cm and the throat h eight was increased from 0.897 to 1.151 cm (0.353 to 0.453 in). The perform ance enhancements were in qualitative agreement with the system design pred ictions of the Blaze II chemical laser model, Three-dimensional computation al fluid dynamics calculations using the general aerodynamic simulation pro gram code confirmed the principle design change of moving the iodine inject ors closer to throat.