Advanced mixing nozzle concepts for COIL

Abstract

An advanced mixing nozzle concept has been developed for high chemical efficiency, high pressure recovery chemical oxygen-iodine laser applications. This concept incorporates the use of mixing tabs mounted at the nozzle exit plane for generating structured streamwise vorticity for mixing enhancement. The tab vortex generators produce strong streamwise vortices for mixing entrainment of highly compressible mixing layers. The optimal tab configuration, dimension, ramp angle relative to the flow direction, and tab spacing were determined by CFD analyses. The CFD computations show the entrainment and mixing produced by these mixing tabs are very efficient. The predicted mixing effectiveness of this nozzle configuration has been validated by experimental Pitot pressure scans of a three-blade nozzle hardware assembly.