Effects of film flow rate on falling film flow with dominant evaporation and simultaneous evaporation and boiling

摘要: Numerous industrial applications of falling film flows alongside its heat and mass transfer complexities appreciate some deep detailed studies. In order to recognize the influences flow rate on modality coefficient, R-245fa at saturation pressure 123.8 kPa around horizontal tube has been simulated different Reynolds numbers 357, 500, 900 1200 two wall fluxes (6 36 kW/m2) by which dominant evaporation simultaneous boiling contributes. Present numerical model is acquired based volume fluid two-phase method Lee phase change model. comparison with experimental data, can accurately simulate sole boiling. Variation thickness after change, velocity temperature profiles utilized discover behavior coefficient. The results show that increasing number increases coefficient convective evaporation. values are 1600, 1605, 1790 1845 W/m2-K, respectively. But when also contributes higher flux, enhancement decreases portion amount total determined challenge decreasing 2800, 2400, 2515, 2425 W/m2-K calculated as coefficients respective for q = 36 kW/m2.