Numerical assessment of ejector performance enhancement by means of two-bypass inlets

The pursuit of high efficiency ejectors has been the target of researchers since the invention of these devices. In the present study, numerical work on an ejector with one bypass inlet (with different inlet widths) and two bypass inlets (with different bypass inlet positions) was proposed to enhance performance. The entrainment ratios when the bypass inlet and secondary inlet were under different pressures were also analyzed. In comparison with the original ejector, the ejector with one bypass inlet had better entrainment performance, and an optimal width of the bypass inlet for the highest entrainment ratio was found. In addition, the performance of the ejector with two bypass inlets was superior to that of the ejector with one bypass inlet, when the primary or induced pressure exceeded the designed value. In comparison with the original ejector, the largest increase of entrainment ratio was 48.93% for the ejector with two bypass inlets and 34.88% for the ejector with one bypass inlet. When the bypass inlet pressures differed from the induced pressure, the optimal operational scheme for high entrainment ratio was that the induced pressure should be the maximum value, and the first bypass pressure should be the minimal value.