Numerical estimation of non-equilibrium condensation in steam ejector

다국어 초록 (Multilingual Abstract)

KEjectors are commonly used in aerospace, chemical and nuclear industries to generate low pressures and thereby passive pumping, by utilizing readily available high pressure steam. In supersonic ejectors there is a possibility of steam condensation inside the nozzle during the rapid expansion process. The formation of droplets can change the ejector performance substantially. Majority of the studies reported in literature neglect the effect of condensation because of the difficulties in modeling. To make numerical predictions of the flow and mixing inside an ejector, the condensation of steam is to be accounted using suitable condensation models reported in the literature. In a supersonic expansion inside a nozzle, because of the high velocity and expansion rate, the condensation process departs far away from the equilibrium state. This type of non-equilibrium condensation is numerically modeled using additional transport equations which are used to compute the mass fraction of condensate generated by the phase change process. In the present work a 2-equation non-equilibrium condensation model with ANSYS FLUENT is used study the flow characteristics. The methodology is validated against experimental studies reported in the literature and used to thoroughly examine steam flow in a supersonic ejector.

목차 (Table of Contents)

• ABSTRACT
• 1. Introduction
• 2. Methodology
• 3. Discussion
• 4. Concluding remarks
• References