Numerical investigation on the mixing process in a steam ejector with different nozzle structures

► We study the effects of five kinds of nozzle shapes on the ejector performance. ► The elliptical and rectangular nozzles decrease the ejector performance. ► The cross-shaped and square nozzles improve the entrainment ratio of the ejector. ► We clarify the mixing process by vortex distribution and internal energy variation. ► The causes of the ejector performance variations are studied qualitatively.