An Experimental and Theoretical Investigation of Multiple Ducted Streams with a Periodic or a Steady Supersonic Driver Flow

摘要

An experimental and theoretical investigation of a supersonic-subsonic, two-dimensional planar, constant area ejector with a periodically pulsed or a steady driver flow is discussed. A large scale fluidic oscillator was developed to partially pulse the driver flow at frequencies up to 250 Hz. A wide range of ejector flow conditions were experimentally investigated with three values of ejector mixing duct length-to-width ratios. Driver flow frequencies of 142 Hz and 250 Hz were used in the ejector experiments and a complete set of steady driver flow experiments was conducted. A one-dimensional, quasi-steady control volume analysis was successfully employed to model these ejector flows. Unsteady ejector flows were found to be modeled well by the quasi-steady analysis. Both steady and unsteady ejector flow performance parameters were accurately predicted by the one-dimensional analysis with the exception of the pressure recovery characteristics observed. Experimentally determined compression ratios were about 25% lower than predicted by the analysis. The pulsation of the driver flow was found to have little effect on ejector operation.