Expansion of a Very Low Quality Two-Phase Fluid Through a Convergent-Divergent Nozzle

Abstract

Flow in de Laval nozzles of high pressure, low-quality steam-water mixtures was investigated to determine the resulting mass flow rates and to acquire design criteria information. Qualities ranged from 0 to 20 percent and pressures up to 1000 psia. Comparisons of the experimental data to three simple models: (a) isentropic expansion; (b) frozen composition; and (c) slip flow, showed satisfactory correspondence at all conditions except for qualities very close to saturated liquid. Observation was made that a condition similar to shock resulted when the nozzles were overexpanded.

Choked Flow Characteristics of Subcritical Refrigerant Flowing Through Converging-Diverging Nozzles

“…where ψcal represents the calculated value by HEM [22] or Henry-Fauske model [20]. Figure 7 presents the values of the relative errors between the model predictions and the experimental results for the critical mass flux.…”

“…HEM [22] and Henry-Fauske model [20] are the two common methods to predict the critical mass flux of the nozzles. Thus the experimental values are compared to the calculated results of the two models in this paper.…”

“…Thus the experimental values are compared to the calculated results of the two models in this paper. The choked mass flux prediction of HEM [22] is:…”

“…Ozaki et al [21] reported that the relative error between homogeneous equilibrium model (HEM) [22] predictions of the critical nozzle flow rate and their tested data was within 5% in the R744 ejector expansion refrigeration system. Elbel et al [23] investigated the critical mass flux of the convergingdiverging motive nozzle in the R744 ejector expansion refrigeration systems, and found that the deviations of the HEM predictions and the Henry-Fauske model predictions from the experimental mass flow rates are −10% ~ −20% and −5% ~ −10% respectively.…”

Transient flashing propellant flow models to predict internal flow characteristics, spray velocity, and aerosol droplet size of a pMDI

“…The method developed by Starkman et al (1964) is used to determine critical (choked) discharge for a given fluid pressure and temperature in the upstream reservoir. The ratio of downstream and upstream pressures across the orifice is systematically reduced from 1 to 0 in small steps.…”