Mixing in an ejector involves the process of combining fluids in a system using an ejector to induce mixing. This can be employed in various applications such as chemical processing, fluid mixing, and even propulsion systems. The design of the ejector and the flow characteristics play a crucial role in ensuring efficient mixing within the flow field. The current CFD study relies on the reference paper “ Visualization and Validation of Ejector Flow Field With Computational and First-Principles Analysis”.

Figure 1: Schematic of ejected sections

Simulation Process

Reference paper provides the design plan of the ejector apparatus that we can use, shown below. Having divided into proper sections, a structured grid then performed using ANSYS Meshing, leading to 200200 cells. Axisymmetric planar mode is opted for due to the symmetrical design of ejectors. This feature effectively decreases computational costs by 50%. The ideal-gas density model is employed in the analysis of various engineering and scientific problems involving ideal gas behavior, such as in the study of compressible flow.

Figure 2: Dimensioned drawing of ejector

Post-processing

The simulation results show fluid flow behavior through an ejector, focusing on the mixing area. The pressure contour indicates a high-pressure region at the inlet (red) that rapidly decreases as the flow moves through the narrow throat, expanding into a lower-pressure region (blue/green) downstream. The velocity field reveals acceleration through the throat, reaching maximum velocities in this region, followed by deceleration and mixing in the expanded section downstream. These patterns are characteristic of compressible gas flow through an ejector, with the ideal gas model capturing the compressibility effects. The mixing process is evident in the velocity field, where shear layers and recirculation zones can be observed in the expansion region, promoting mixing between the primary and entrained flows.