Vertically upward two-phase flow with a highly viscous liquid-phase in a nozzle and orifice plate

Water and glycerine were used to produce solutions with nominal liquid viscosities of 1, 100, 250 and 550 mPa s. These liquids flowed concurrently with air into a conical nozzle. Measurements of discharge momentum fluxes, inlet void fractions and pressure drops were made for subsonic and sonic discharges. Liquids with nominal liquid viscosities of 1 and 450 mPa s were used to do similar tests on a sharp edged orifice plate. The orifice had the same discharge diameter as the nozzle. The flow pattern developed in the long supply pipe was annular up flow. The nozzle data are shown to be consistent with the annular flow model provided the wall and interfacial shear stresses are included. The orifice plate is shown to behave in a similar manner to the nozzle, despite the very different flow path.