Effect of geometrical factors interactions on design optimization process of a natural gas ejector

Enhancing the ejector entrainment ratio plays an important role in the ejector performance. In this article, a surrogate-based optimization approach along with computational fluid dynamics technique has been employed to optimize the entrainment ratio of a single-phase ejector working with natural gas. Nine ejector geometrical factors have been varied to maximize the ejector entrainment ratio. Validation results of the presented computational fluid dynamics model were in a good agreement with the experimental data from the literature with an average error of 0.6% in the critical mode. Reported results showed that the optimum design achieves entrainment ratio of 19.45% at 12, 2, and 5.2 MPa motive pressure, induced pressure, and discharge pressure, respectively. Moreover, the primary nozzle convergent angle and throat length are insignificant factors. Furthermore, secondary nozzle inclination angle has a minor effect on the entrainment ratio of the optimum design.