A Numerical Study of a Water–Steam Ejector for Steam Exhausting with OpenFoam—The Effect of Steam-Bubble Diameter

A water–steam ejector can be used for steam exhausting in some equipment, such as sterilization systems in hospital facilities. In this type of ejector, a water jet in the center is used to entrain and transport steam from the sterilization chamber. The performance of the ejector, which is a function of the pressure in the sterilization chamber and the temperature of the water, is crucial for the reduction in water and energy consumption. The numerical simulation of this type of device is challenging because of the mass, momentum and energy exchange between the phases. In this study, numerical simulations of an axisymmetrical model of a water–steam ejector considering mixing and heat and mass transfer by condensation are shown. The Euler–Euler method with OpenFOAM v2312 was used. The influence of the steam-bubble diameter was studied, and the results were validated with a previously published experimental report, which showed an agreement of approximately 2.5% for the adopted mesh size. The proposed solution may be appropriate for rapid design procedures for these types of devices.