AN ANALYTICAL AND EXPERIMENTAL STUDY OF LOW PRESSURE AIR EJECTOR PUMPS

An approximate mathematical analysis of Venturi-type low pressure air ejectors is made. This analysis is extended to shapes other than a Venturi. The analysis predicts that the ratio of secondary air flow to primary air flow will be a function of (1) the temperature ratio of the primary and secondary air, (2) the restriction of the secondary circuit, (3) the ratio of the area of the secondary circuit to the area of the primary circuit, and (4) a shape factor. The shape factor is calculable for a Venturi-type ejector but must be determined experimentally for other shapes. The predictions of the analysis are shown to be in reasonably good agreement with experimental results.