Experimental study of two phase upward flow in vertical one-inch pipe

Zhuoran Dang, Purdue University


Due to the similarity of hydraulic characteristics between one-inch vertical pipe and BWR and PWR rod bundle, the interfacial characteristics of this geometry could be used to analyze and predict the interfacial behavior in the reactor. Currently, a complete and reliable database covering the whole flow regimes for one-inch vertical pipe is needed. Thus, this research aimed for the experimental study of co-current two-phase upward flow in vertical one-inch pipe.

Global void fraction database ranging from bubbly flow to annular flow regime at atmospheric pressure was obtained using two ring electrode impedance meter. Gamma densitometer system, multi single-sensor conductivity probe were introduced for the comparison with global void fraction database in order to ensure its accuracy. Drift flux model was also evaluated using the global void fraction result. A self-organizing neural network was used to identify flow regimes using the signals from impedance meter. Local experiment was conducted in different gas and liquid velocities using four-sensor conductivity probe. The measured local interfacial parameters include bubble velocity, time-averaged local void fraction, and interfacial area concentration. The data covers both radial and axial development of the two-phase flow structure. The obtained database could be used for the evaluation and analysis of current available interfacial area transport equation.