Statistical comparison of two-phase flow, void fraction fluctuations in a microgravity environment

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: 82-85.Issued also on microfiche from Lange Micrographics.A two-phase flow experiment was flown aboard the NASA KC-135 zero gravity aircraft to test void fraction sensors and collect void fraction data under the unique conditions of microgravity. Void fraction measurements were made by two capacitance void fraction sensors and trapped liquid between two quick closing valves. A statistical method involving a probability density function and moments of a distribution were developed to analyze the void fraction fluctuations for uses as a possible flow regime identifier. Results show that slug flows exhibit both unimodal distribution and multi-modal distribution in the probability density function while annular flows have unimodal distribution with a peak at high void fractions. It was found that the variance of void fluctuations for slug flows tended to be larger than annular flows. Annular flows have negative coefficients of skewness and kurtosis. Slug flows exhibited both positive and negative coefficients of skewness and kurtosis. The combination of probability density function and variance of the void fraction fluctuations was found to be the best flow regime identification tool