Experimental investigation of countercurrent liquid-vapor interactions and their effect on the friction Factor

Abstract

An experimental test facility was constructed to determine the vapor flow influence on the friction factor of countercurrent liquid flowing in small channels. The fluids used were water and air. The friction factor for liquid flowing in three different grooves with channel angles of 20°, 40°, and 60° was evaluated to determine the influence of the vapor flow for a velocity range of 0–10 m/s. The vapor flow was shown to significantly influence the friction factor of the liquid, due to the frictional interaction at the vapor-liquid interface. As expected, increasing the velocity of the vapor flow resulted in an increase in the friction factor of the liquid. The amount of this increase was shown to depend on the ratio of the average vapor velocity to the average liquid flow velocity. For grooves with larger channel angles, the vapor flow velocity was shown to have a more significant influence on the friction factor of the liquid. The wave height at the liquid surface was also found to affect the friction factor, with larger waves resulting in an increased friction factor.