Supersonic diffuser for pressure recovery in SCOIL system

Abstract: Classical supersonic chemical oxygen iodine laser (SCOIL) systems operate under a low total pressure of nearly 18Torr (2400Pa) with cavity pressure being in the range 3Torr (400Pa) and Mach number of 1.7. These systems handle high flow rates and hence an efficient supersonic diffuser (SD) is a critical first step towards an open-cycle operation, which may be followed by a multi-stage ejector system. The present study discusses the various aspects in the design of a supersonic diffuser for a twin 10kW COIL module source which employs flow rates of 100gs−1 in each module. The results of computational studies based on 3-D, viscos compressible flow, k–ε turbulence formulation for the supersonic diffuser geometry have also been discussed. The experimental results from a single-module test of the supersonic diffuser show that a total recovered pressure of nearly 7Torr is achieved at the diffuser exit. [Copyright &y& Elsevier]