Momentum transfer in a two phase liquid-liquid system in cocurrent stratified flow
Doctor of Philosophy
The two phase system of water and kerosene in cocurrent stratified turbulent flow in a closed rectangular channel was studied. Profiles of mean velocity were measured in both phases by means of a hot-wire anemometer, for various combinations of flow rates of the two phases. The range of Reynolds numbers covered was from about 1900 to 4000 for the kerosene phase and from 2400 to 6200 for the water phase. This Reynolds number is defined as the mass flow rate per unit channel width divided by the fluid viscosity. The velocity profiles in each phase for all runs could be represented by an empirical equation of the form: U/U*=a'+b' h+c'h2+d' h2n+e'h2 n'+1. This form of the equation was derived from a combination of the expressions given by Pai for the two cases of turbulent Poiseuille and Couette flow between parallel plates. The parameters necessary to define the profiles by this expression could be correlated as functions of the water and kerosene Reynolds numbers. The wall friction coefficient as determined from the profiles with the aid of the above expression was also correlated as a function of the water and kerosene Reynolds numbers. The same correlation equation was found to be valid for both the kerosene and water walls merely by interchanging the Reynolds numbers in the equation. The interfacial shear coefficient, however, was found to be primarily a function of the Reynolds number of the upper (kerosene) phase. Furthermore, the function apparently depends upon the sign of the interfacial shear (i.e. which phase is moving the faster). A difference in shear across the interfacial region was found, which could be explained on an order of magnitude basis by a consideration of the rate of change of interfacial wave momentum.