Comparison of one-dimensional solutions with Fabri theory for ejectors

SummaryEjector performance for constant area or constant pressure mixing is theoretically examined using a one-dimensional approach as well as the inviscid, theory of Fabri. The variety of solutions generated by the one-dimensional approach is shown to be severely restricted by the Fabri theory. This restriction produces solution regions that are not allowed, as well as regions where the back pressure alters the secondary flow rate. Operation with a slightly supersonic secondary flow is examined, but may not be realized due to shock wave formation. Operation at a high supersonic value for the secondary flow provides appreciably poorer ejector performance than is attainable when this flow is subsonic.