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

A chemical oxygen-iodine laser (COIL), the VertiCOIL device, was transferred from the Air Force Research Laboratory (AFRL) to the University of Illinois 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 23% were achieved; these are the highest reported chemical efficiencies with room-temperature nitrogen diluent. A long duration, high chemical efficiency test was demonstrated with nitrogen diluent; a chemical efficiency of 18.545 at 30 mmol/s of chlorine was maintained for 35 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 height was increased from 0.897 to 1.151 cm (0.353 to 0.453 in). The performance enhancements were in qualitative agreement with the system design predictions of the Blaze II chemical laser model. Three-dimensional computational fluid dynamics calculations using the general aerodynamic simulation program code confirmed the principle design change of moving the iodine injectors closer to throat.