Measurements and correlations of frictional single-phase and two-phase pressure drops of R-410A flow in small U-type return bends

CFD Analysis for Non-Newtonian Pseudo Plastic Liquid Flow Through Small Diameter U-BEND

“…Practical simulations can also be performed by solving the filtered Navier-Stokes equations using a Large-Eddy Simulation (LES) or by solving the Reynolds Average Navier-Stokes (RANS) equations with an appropriate closure model for the Reynolds stress (Jayanti et al, 1990;Brockmann, 1993;Bergstrom et al, 1998;Wang and Shirazi, 2001;Breuer et al, 2006;Berrouk and Laurence, 2008;andZhang et al, 2009, 2010, etc.). Chen et al (2004) also studied the two-phase frictional pressure drop for R-410A in four small diameter U-type return bends. Mazumder (2009) investigated erosion in a 180 0 U-bend using Fluent 6.3.…”

An improved correlation for two-phase pressure drop of R-22 and R-410A in 180° return bends

“…Recently, Chen et al [10,11] studied water-air mixture and R-410A flows, respectively, through different bend geometries. Chen et al [11] proposed a correlation with which they predicted most of Geary's [7] and their own experimental data within ±50% error bands.…”

“…In the present work, a dataset of 241 experimental points obtained from [7,11] was used to derive a new, improved correlation that can be applied within the whole two-phase region for smooth-tube return bends. This study was partially reported in [12,13].…”

Evaluation of two-phase evaporation pressure drop correlations for low refrigerant mass flux.

“…These correlations include Geary (1975), Chen et al (2004b), Domanski and Hermes (2006) and Paliwoda (1992) (Silva Lima & Thome, 2012b). …”

“…He suggested the use of a single-phase correlation by Ito (1959) (Ito, 1959) for vapor higher qualities assuming pure-vapor pressure gradients. Chen et al (2004b) used his own database and added the data of Geary (Ito, 1959). They suggested a similar correlation to Geary model, but suggested different empirical factors, added the effects of the Weber number and used mixture Reynolds number, rather than vapor-phase Reynolds number as in original Geary correlation.…”