| Abstrak/Abstract |
The present experimental study aims to investigate the performance of flow pattern on
heat transfer process of gas-non-Newtonian liquids two-phase flow in a microchannel.
The square copper microchannel was used with side length of 8 x 10-4 m. Some
working liquids used in this study including, water, 0.2%wt CMC (Carboxymethyl
Cellulose) aqueous solutions, 0.4%wt CMC, and 0.2%wt XG (Xanthan Gum). The
nitrogen was used as the working gas. The liquid apparent velocity, jL was varied in
range of 0.05-1.0 m/s. The gas apparent velocity, jG was 0.26-7.81 m/s. Some of DPTs
(Differential Pressure Transducers) were used to measure the pressure drop. In the
present study, a constant heat flow of 12.08 kW/m2 was used. The temperature of the
channel’s wall was measured by using T-type thermocouple, which is located on the
copper channel as heating section. Moreover, the flow patterns were captured by using
a high-speed video camera. The results indicate that four types of flow patterns occur
in the present study including bubbly (BB), slug (SL), slug-annular (SA), and churn
(CH) flow. The coefficient of convective heat transfer on the CH flow shows a highest
value than other flow patterns. However, the highest-pressure gradient was obtained in
the CH flow pattern both in the upstream of heating and in heating sections. Moreover,
Kawahara et al., (2011) and Rezkallah (1986) correlations gives a good agreement
with present experimental data of pressure gradient and coefficient of convective heat
transfer, , respectively. However, the best performance index of heat transfer process
in present gas-non-Newtonian two-phase flow is found in the slug flow |
