TY - JOUR
T1 - A visual study of two-phase flow patterns of HFC-134a and lubricant oil mixtures
AU - Wongwises, Somchai
AU - Wongchang, Tawatchai
AU - Kaewon, Jatuporn
AU - Wang, Chi-Chuan
PY - 2002/1/1
Y1 - 2002/1/1
N2 - The two-phase flow patterns of HFC-134a with lubricant oil mixtures inside a smooth horizontal tube were experimentally elucidated. Tests were performed in an inside diameter of 7.8 mm having a lubricating oil concentration of 5%. Tests were made of mass fluxes ranging between 150 and 590 kg/m2 s. The most obvious difference from oil-free cases reported is the presence of froth flow pattern. Apparently, this flow pattern is related to the increase of surface tension and viscosity. With the presence of lubricant oil, the onset of transition from stratified flow region to annular flow regime shifted to a lower value of superficial gas velocity. In addition, the tearing phenomenon of the refrigerant-oil mixtures may be related to its relevant properties such as wettability and surface tension.
AB - The two-phase flow patterns of HFC-134a with lubricant oil mixtures inside a smooth horizontal tube were experimentally elucidated. Tests were performed in an inside diameter of 7.8 mm having a lubricating oil concentration of 5%. Tests were made of mass fluxes ranging between 150 and 590 kg/m2 s. The most obvious difference from oil-free cases reported is the presence of froth flow pattern. Apparently, this flow pattern is related to the increase of surface tension and viscosity. With the presence of lubricant oil, the onset of transition from stratified flow region to annular flow regime shifted to a lower value of superficial gas velocity. In addition, the tearing phenomenon of the refrigerant-oil mixtures may be related to its relevant properties such as wettability and surface tension.
UR - http://www.scopus.com/inward/record.url?scp=0036645033&partnerID=8YFLogxK
U2 - 10.1080/01457630290090464
DO - 10.1080/01457630290090464
M3 - Article
AN - SCOPUS:0036645033
VL - 23
SP - 13
EP - 22
JO - Heat Transfer Engineering
JF - Heat Transfer Engineering
SN - 0145-7632
IS - 4
ER -