Mathematical Modelling of Two‐Phase Transonic Compressible $CO2$ Flow Through Heat Pump Ejector

In this paper mathematical modelling of a two‐phase flow occurring in an ejector which replaces a throttling valve typically used in a heat pump cycle is numerically considered. The geometry of the model is three dimensional taking one cross‐sectional symmetry plane into account. In such model different discretizations were generated to study an influence of the rapidly changing quantities on the system operation. The density variations are defined using real gas model i.e. Redlich‐Kwong for $CO2$ and REFPROP databases were employed. Both models produced similar character of the results. In addition, it was observed that the effects of wall roughness value defined as in planned experiments in such high speed systems can be neglected.