A COMPUTER-BASED HOT-FILM TECHNIQUE FOR 2-PHASE FLOW MEASUREMENTS

This paper describes the development of a novel computer-based hot-fil m anemometer measurement technique for the investigation of the local structure of two-phase flows. The technique enables the total signal t o be separated into the parts corresponding to bubbles and continuous phase, from which the local volume fraction can be evaluated. Evaluati on procedures are also presented for analysing the remainder of the si gnal corresponding to the turbulent continuous phase after eliminating the bubble signals. Methods are described and discussed for the evalu ation of the longitudinal mean velocity, normal stress, autocorrelatio n and energy spectrum. Finally typical results for a vertical up-flow of a bubbly kerosene/water mixture are presented.