Isothemal Air-Water Two-Phase Flow through a Horizontal Capillary Return Bend

Autor: Tohru Fukano, Akira Kariyasaki, Akiharu Ousaka, Masazumi Kagawa
Rok vydání: 1996
Předmět:
Zdroj: TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B. 62:115-121
ISSN: 1884-8346
0387-5016
DOI: 10.1299/kikaib.62.115
Popis: Air-water two-phase flow phenomena through a horizontal capillary return bend are investigated focusing on the flow pattern and total pressure loss of the bend to obtain fundamental knowledge of the important parameters for designing compact heat exchangers. The pipe inner diameter (D) was 2.4 mm, and the radii of curvature of the bend tested were 5D, 10D and 20D. The flow patterns observed in this experiment were bubbly, intermittent and annular flow. The superficial velocity of air ranged from 0.05 m/s to 15 m/s and that of water, from 0.05 m/s to 2 m/s. It is clarified that the total pressure loss of the bend due to single-phase flow of water in capillary tubes (laminar flow region) can be predicted from the experimental correlation proposed by White [Proc. R. Soc., Ser. A, 123(1929), 645-663] within about 14% accuracy. A two-phase multiplier of bend loss is defined and we propose its relationship with the liquid Reynolds number and Dean number.
Databáze: OpenAIRE