TITLE:
Numerical Study on the Effects of Contraction Ratio in a Two-Phase Flow Injection Nozzle
AUTHORS:
Haider Ali, Kyung Won Kim, Jae Sik Kim, Jong Yun Choi, Cheol Woo Park
KEYWORDS:
Flow Injection Nozzle, Nozzle Throat, Contraction Ratio, Gas-Liquid Flow, Mass Transfer
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.6 No.1,
March
8,
2016
ABSTRACT: The Euler-Euler numerical method was used to investigate the effects of contraction ratio on twophase
flow mixing with mass transfer in the flow injection nozzle. The geometric shape of the nozzle
was modified to improve carbonation efficiency. A gas inlet hole was created to increase the
flow mixing of CO2 with water. A nozzle throat was also introduced to increase the gas dissolution
by increasing flow rates. Various contraction ratios of nozzle throat, inlet gas and liquid velocities,
and gas bubble sizes were employed to determine their effects on gas hold-up, gas concentration,
and mass transfer coefficient. Results revealed that the flow injection nozzle with high contraction
ratios improved carbonation because of high gas hold-up. Gas concentration was directly related
to contraction ratio and gas flow velocities. Carbonation reduced when high liquid velocities and
large gas bubbles were employed because of inefficient flow mixing. This study indicated that flow
injection nozzle with large contraction ratios were suitable for carbonation because of their ability
to increase gas hold-up, gas concentration, and mass transfer coefficient.