Numerical analysis on ejector performance with varying geometric parameters of chevrons.

The entrainment ratio of the ejector in an ejector refrigeration system (ERS) directly depends on the mixing between the primary fluid (generator) and the secondary fluid (evaporator). In this analysis, the effect of variation of chevron tip angle 𝛽 for a fixed number of chevrons N on the entrainment ratio has been studied. The analysis has been conducted in a steady state by solving the compressible and turbulence equations and rotational periodic boundary conditions with water vapor as the working fluid. The shear layer thickness for the chevron tip angle 60◦ is not only higher but also conserved downstream, resulting in the highest entrainment ratio of 0.4705. The variation of secondary fluid flow angle for different chevron tip angles is a significant parameter for the increment in the entrainment ratio. Also, the optimum L/D% for the given working and geometry conditions lies within the range of 68% ± 5% for all numbers of chevrons. There has been no improvement in the entrainment ratio with the variation in the penetration angle 𝛼.