a Mechanical. Eng. Dept., Shoubra Faculty of Eng., Zagazig University, Cairo, Egypt
In this research work, an experimental study was performed on the effects of surface condition and boiling liquid combinations on the heat transfer performance of the heated surface during saturated nucleate pool boiling. To meet the aforementioned needs, a pool boiling test apparatus was designed and constructed to achieve heat transfer
measurements from seven horizontal upward facing aluminum alloy 6061 plates. These tested plates were: mirror finish, three mechanically treated surfaces and three chemically treated surfaces. All surfaces are tested in pools of saturated demineralized water and acetone for free convection and isolated bubble regimes. Tests showed that
the enhancement in the nucleate pool boiling heat transfer coefficient reached up to 600% due to the variation in the roughness of the heated surface. From pool boiling heat transfer data, the size distribution function of stable vapor bubbles in active nucleation sites for each one of the seven heated surfaces was deduced. Finally, the size
distribution function constants were correlated with the surface roughness parameter (RP).