Numerical investigation of a two-stage ejector based on a constant rate of momentum change: performance analysis and optimisation
DOI:
https://doi.org/10.24425/ather.2025.156597Abstract
A two-stage ejector based on a constant rate of momentum change is a geometrical arrangement of a single-stage ejector to further improve its performance, utilising water vapour as a working fluid for both primary and secondary flows. Creating an additional secondary inlet in the single-stage ejector helps to further entrain the secondary mass flow, resulting in a better entrainment ratio. The present study utilises the constant rate of momentum change, and a 1D gas dynamic approach to compute the geometrical profile and flow parameters using MATLAB. The numerical software ANSYS Fluent 18.0 is utilised to analyse the two-stage ejector geometry. The global performance ejector entrainment was computed at on and off design conditions. The results show that the two-stage ejector entrainment ratio is significantly higher than that of the previously studied single-stage ejector. The entrainment ratio of the two-stage ejector increases to reach the on-design value of operating conditions, and then starts decreasing.References
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