Experimental and simulation investigation of the impact of rotational speed on the performance of radial-flow gas wave ejector

Abstract

The gas wave ejector (GWE) is a device that enables energy transfer between gases at different pressures through pressure waves. We conduct an experimental and simulation study on a novel radial-flow GWE, named DUT-R1, designed to harness centrifugal force to enhance mass and energy transfer efficiencies. Considering the significant influence of rotational speed (n) on the pressure waves and flow losses, we examine the relationship between the n of the DUT-R1 and both its ejection rate (ξ) and total efficiency (ηT).Experimental data demonstrate that the GWE can attain the highest ξ and ηT at an optimal designed rotational velocity (nd) when the pressure ports remain fixed. Simulations suggest that the primary cause can be attributed to the disruption of the ideal wave system. And when the equipment is equipped with ports matched to the nd, a consistent increase ξ is observed as the nd increases from 2000 r/min to 4000 r/min, resulting in a maximum improvement of 13.25 %. The simulation results demonstrate that increasing n enhances the suction capacity of the equipment through the inputting of shaft power (P). However, ηT initially increases and then decreases as the nd increases, with a maximum improvement of 11.86 %. The simulation provides an explanation for the observed variations in ηT during the experimental investigation by illustrating that flow losses initially decrease and then subsequently increase with an increasing value of n.