<title>Modeling of uniform droplet singlet oxygen generators</title>

Abstract

Electronically excited oxygen, O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ), is the power source that drives chemical oxygen iodine lasers. A new type of singlet oxygen generator has been both analytically and experimentally characterized. This new generator uses uniformly sized droplets of basic hydrogen peroxide (BHP) as the liquid phase reaction surface. The gaseous chlorine and O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ) flow between a multitude of droplets in the generator. The fraction of chlorine that is converted into O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ) depends on the coupled gas and liquid flow fields, diffusive mass transport, and homogeneous gas, liquid, and interface chemical reactions. A 1D flow/chemistry code has been developed and used to investigate the effects of the choice of parameters associated with the two-phase chemistry and transport on the chlorine utilization, O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ) yield, and the efficiency of converting chlorine into O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ). Predicted sensitivities to flow conditions, and the chemistry of the reactive media are presented. In particular, modeling results that identify dominant physical processes, and appropriate mathematical models are discussed. Analysis and a review of available information on the chlorine reaction with BHP in O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ) generators indicates that the performance of the UDOG should be dominated by the gas-liquid interfacial and internal liquid chemical reactions and diffusion processes. A major part of the modeling effort has been to investigate this assumption and question it. A surface reaction model provides much better agreement with measurements made in a uniform droplet O<SUB>2</SUB>(<SUP>1</SUP>(Delta) ) generator.