Transient numerical simulations are carried out to investigate the liquid-gas interfacecharacteristics associated with liquid film cooling flows.A two-dimensional axisymmetricmulti-phase numerical model using finite v...Transient numerical simulations are carried out to investigate the liquid-gas interfacecharacteristics associated with liquid film cooling flows.A two-dimensional axisymmetricmulti-phase numerical model using finite volume formulation is developed.The model hasbeen validated against available experimental data for liquid-film cooling flows inside tubes.The model has been used to predict the interface characteristics for a variety of imposedparameters and momentum flux ratios under cold flow conditions wherein both the coolant andmainstream are maintained at the same temperature.Disturbance waves are observed at theliquid-gas interface for coolant flows above a critical value and after a finite distance from theinlet.The distance toward the wave inception point increased with the increase of momentumflux ratio.However,at higher momentum flux ratios,the properties of the disturbance wavesdid not vary significantly.The parameters related to the liquid-gas interface waves,namely,wave velocity,frequency,amplitude and wave length have been analyzed in detail.Analysisindicates that the liquid entrainment is due to the shearing of the disturbance wave crest.展开更多
文摘Transient numerical simulations are carried out to investigate the liquid-gas interfacecharacteristics associated with liquid film cooling flows.A two-dimensional axisymmetricmulti-phase numerical model using finite volume formulation is developed.The model hasbeen validated against available experimental data for liquid-film cooling flows inside tubes.The model has been used to predict the interface characteristics for a variety of imposedparameters and momentum flux ratios under cold flow conditions wherein both the coolant andmainstream are maintained at the same temperature.Disturbance waves are observed at theliquid-gas interface for coolant flows above a critical value and after a finite distance from theinlet.The distance toward the wave inception point increased with the increase of momentumflux ratio.However,at higher momentum flux ratios,the properties of the disturbance wavesdid not vary significantly.The parameters related to the liquid-gas interface waves,namely,wave velocity,frequency,amplitude and wave length have been analyzed in detail.Analysisindicates that the liquid entrainment is due to the shearing of the disturbance wave crest.
