Analysis of Expansion Waves Appearing in the Outlets of Two-Phase Flow Nozzles

Abstract

Two-phase flow nozzles are used in the total flow systems of geothermal power plants and in the ejector refrigeration cycle. The purpose of the present study is to theoretically elucidate the characteristics of expansion waves at the outlets of supersonic two-phase flow nozzles. Two-dimensional basic equations for compressible two-phase flow were derived by incorporating the equation of momentum transfer between the phases into equations of gas dynamics. In this study, the theoretical analyses were carried out by focusing on momentum-relaxation phenomena in high-speed vapor-mist flow. Expansion waves occurring right after two-phase flow nozzles were calculated by using the CIP method. The calculated expansion curves were compared with the experimentally obtained curves, and the two showed close resemblance.

An Accurate and Efficient Look-up Table Equation of State for Two-Phase Compressible Flow Simulations of Carbon Dioxide

“…Figure shows that the two-phase speed of sound of the HEM has two discontinuities for α v = 1 and α v = 0, which implies discontinuities through the saturation curve. These discontinuities are model-dependent, as discussed by Flȧtten and Lund, and Nakagawa et al…”

“…Figure 4 shows that the two-phase speed of sound of the HEM has two discontinuities for α v = 1 and α v = 0, which implies discontinuities through the saturation curve. These discontinuities are model-dependent, as discussed by Flaṫten and Lund, 44 and Nakagawa et al 50 In the system composed of eqs 1, 2, 3, there are four unknowns but only three equations. In order to close the system, an EoS is required to compute the pressure p(e, ρ) from the density and the specific internal energy.…”