ABSTRACT

Studies of the nature of the flow development are performed for air-water vertical annular flow. Two forms of liquid injector (porous wall and central axial jet injectors, respectively) are employed in the experiments. Their effects on development of flow parameters (e.g. entrained fraction, film thickness and pressure gradient) are further analysed and compared with the published correlations. Poor agreement is observed which is ascribed to the difficulty in modelling the development of the interfacial structure, in particular the disturbance waves and the entrained droplets.