To explore different flow phenomena in micro-channels, different inlet sections were used in the experiments, as shown in Fig. 3.The inlet section, presented in Fig. 3a, led the gas–liquid mixture
directly to the micro-channels. For the other, as illustrated in
Fig. 3b, the mixture was led to flow through a piece of foamed
plastic polymer, a porous material, and subsequently entered the
micro-channels.
In this work, the experiments for each inlet section were conducted
so the air flow rate increased by small increments while
the water flow rate was constant at the desired value. To keep
the flow from boiling conditions, the heat load of 80 W was provided
by a DC power supply during the experiments. The system
was allowed to approach a steady state before the flow pattern
and relevant data are recorded. The uncertainties associated with
different parameters are given in Table 1.