Characteristics of a fluted nozzle gas eductor system

Abstract

Cold flow tests were conducted on a four nozzle and a one nozzle gas educator system. The nozzles employed were fluted with a constant cross sectional area. The four nozzle tests used a mixing stack length-to-diameter ratio, (L/D), 1.5; the single nozzle tests used L/D ratios of2.0, 1.75, and 1.5. The total cross sectional area of the mixing stack was 2/3; for the single fluted nozzle, 2.42. Secondary pumping coefficients, mixing stack pressure distributions, and exit velocity profiles were determined. The pumping performance of the four fluted nozzle system was found to be comparable to a straight nozzle system, showing no specific advantages. The single fluted nozzle system pumping performance showed a slight improvement with increased L/D. The system performance was comparable to the four straight nozzle system at the same L/D. The peak exit velocities of the single fluted nozzle system were higher than those for the four straight and four fluted nozzle systems.