Ejectors are commonly utilized in the chemical process industries but can also be employed for mass transfer processes such as liquid-liquid extraction, gas absorption, stripping, fermentation, hydrogenation, and chlorination. It is clear that before proceeding any CFD simulation, there is strong need for a validation study. This is what we`ve targeted; to validate the experimental data of paper “ Design aspects of ejectors: Effects of suction chamber geometry”, published in Chemical Engineering Science journal.

Figure 1: Schematic of paper`s ejector domain

Simulation Process

A 2D-axisymmetric geometry of the ejector is created. It is meshed with hexahedral (structured) elements of uniform size. Given the Euler-Euler approach, it is decided to use the mixture multiphase model. In our study, the in-build slip correlation between primary and secondary phases are not followed, instead, the slip velocity has been directly specified through a user-defined function (UDF) by using the following definition:

Figure 2: Slip velocity definition based on the paper

Post-processing

Prior to any fluid dynamics analysis, we focus on validating the data given in the paper. In the base paper by Bhutada and Pangarkar, Experimental entrainment rate = 0.00294 kg/s. On the other hand, the current CFD simulation reports the value as 0.00288 kg/s. To put it in a nutshell, there is only 2% error! It entirely corroborates the precision of the study.