The choice of two-phase flow structure model in refrigerant's throttling process

The choice of flow structure model is a key point in cognitive analysis and mathematical modeling of two-phase flows. The problem is particularly difficult in the case of flows with large thermodynamic parameters gradients of two-phase refrigerant. Two-phase refrigerant throttling process, occurring in cryogenics and refrigerating engineering, is a good example of this problem. Both, introductory analysis and theoretical calculations results are often displayed on diagrams called "flow maps". This paper presents flow maps for two-phase refrigerant throttling process in capillary throttling elements. Additionally representation of throttling process progress is proposed. Results of theoretical analysis were confirmed by a set of experiments conducted on test bed allowing full throttling process visualization. The experiments were performed for exemplary flow cases. The experiment results were compared with results obtained by other authors.