Two-phase pressure drop in multiple thick- and thin-orifice plates

• Published in: Experimental thermal and fluid science Vol. 15; no. 4; pp. 347 - 358
• Main Authors: Kojasoy, G., Landis, F., Kwame-Mensah, P., Chang, C.T.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-11-1997; Elsevier Science
• Subjects: Benchmarking; Contraction; Correlation; Energy use; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fluid mechanics; Fluids; Fundamental areas of phenomenology (including applications); Heat losses; Mathematical models; Momentum; Multiphase and particle-laden flows; Nonhomogeneous flows; Numerical methods; Orifices; Physics; Plates (structural components); Shrinkage; singular pressure drop; Singularities; Slip; Thermal expansion; Two phase flow; Viscosity; singular pressure drop; two-phase flow; Test facilities; Pipe flow; R 113 fluid; Perforated plate; Liquid vapor flow; Thin plate; Experimental study; Avionics; Sudden contraction; Cooler; Two-phase flow; Pressure drop; Sudden enlargement; Slabs; Refrigerant fluid
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/S0894-1777(97)00003-4

Two-phase flow pressure changes through singularities such as sudden expansion and sudden contraction of thick- and thin-orifice plates were modeled. The modeling was based on the reversible and irreversible losses through contractions and expansions. The volume-averaged momentum equation and the reversible mechanical energy equation were used to evaluate the irreversibilities. Local slip ratios, which were necessary for the prediction of pressure drop through these singularities, were correlated from a large number of experimental data. To check the validity of the analytical predictions, an experimental test section was designed, and experiments were performed to produce benchmark pressure-drop data for thin- and thick-plate orifices. The working fluid used for these experiments was R-113. The predictive methods developed agree well with the experiments by the authors and with a wide range of two-phase flow test results obtained by others for steam-water systems. A parametric study shows the relative importance of geometry and of the flow variables such as quality, liquid-to-vapor density, and viscosity ratios on the pressure drop multipliers conventionally used in two-phase flows.