Study on gas-liquid two phase flow pattern and pressure drop of micro-pin fin heat sink

Preliminary experimental study on flow pattern and pressure drop of gas-liquid two phase flow of micro pin fin heat sink, using nitrogen and de-ionized water as working liquid, has been carried out in this paper. The result shows that surface tension effect plays a major role when the flow rates of gas and liquid are both low. And the bubbles stagnate between the fins randomly in this stage. The value of C in Chisholm correlation undergoes two evolvement processes, which are caused by the change of surface tension effect and flow pattern, respectively. The M-H model, which is only considered the effect of equivalent diameter, agrees well with the current data(a mean deviation of 9.27%). In low liquid flow rate the L-Mu model can predict experimental data accurately.