Influence of speed of sound in two-phase region on 1-D ejector performance modelling

Highlights: • The characteristics of speed of sound were analyzed for R134a and water. • Speed of sound in two-phase region changed dramatically with conditions. • 1-D ejector performance simulation is influenced by the correlations of speed of sound. • Correlations proposed by Niknam et al. showed a relative better result. Calculating two-phase speed of sound is important to 1-D ejector modelling using wet working fluid. In this study, influences of six correlations on ejector modelling results were investigated. Ejector model based on mass, momentum and energy conservation equations was adopted and real gas properties were used. The characteristics of the predicted speed of sound in two-phase region with pressures and mass fraction of vapor were analyzed. It revealed the predicted speed of sound changed dramatically with mass fraction of vapor under different pressures and discrepancy among these speed values were showed. Based on 1-D ejector model, results showed maximum 0.91% and 8.57% deviations with these correlations when using R134a and water as working fluids, respectively.