Multiphase Flow Regime Identification in Cryogenic Nitrogen using Electrical Capacitance Measurement Technology

Abstract

Understanding and modeling multiphase flow is of vital importance to the design of next-generation cryogenic systems. While many experiments characterizing multiphase flow have been performed on Earth, the behavior of cryogenic systems still needs to be fully described in low gravity and microgravity conditions. As the necessity of cryogenic systems increases for in-space refueling operations, increased heat transfer efficiency, and in-situ resource utilization, the demand for better fluid models, instrumentation, and control systems also increases. In this paper, a capacitance-based flow regime identification algorithm is developed for use with cryogenic systems. Data is collected on a liquid nitrogen system for a wide array of flow regimes in a ½” tube. Quantitative parameters are developed that are able to determine the real-time multiphase flow regime and the algorithm is verified using accepted models, providing much that is needed for the foundation of a multiphase flow regime identification instrument with broad applications in fluid modeling, research, and cryogenic system feedback control.