Experimental Frequency Response Characteristics for Diabatic Two-Phase Flow in a Vertical Monotube Vapor Generator Available to Purchase

This paper presents experimental data on the dynamic behavior of diabatic two-phase flow in a vertical tube with Refrigerant-11 as the working fluid. A detailed description is included of the experimental test facility as well as the instrumentation used for monitoring the variables of pressure, flow, heat flux, and void fraction. Experimental data are presented in frequency response form for inlet impedance (ΔP₁/ΔW₁) and exit void fraction (Δα₃/ΔW₁) at constant heat flux over a frequency range of 0.01 to 10.0 Hz. The data cover inlet subcooling conditions of 14°F and 79°F and two heat flux levels. The experimental results show that the inlet impedance characteristics have fluctuations in amplitude and phase lag with frequency which lead to resonant peaks in the overall frequency response behavior. Exit void fraction characteristics show similar resonant behavior with large phase lag at frequencies above 1 Hz.