Nucleation site density in nucleate pool boiling at saturation on a horizontal smooth stainless steel cylinder: Pure liquids

Nucleate boiling is an effective mode of heat transfer; however, it is still relatively poorly understood. This gap stems from the decades-old difficulty of directly and accurately measuring important boiling parameters such as bubble departure diameter and frequency, bubble growth and wait times, and nucleation site density. In this study, an experimental investigation on the nucleation site density during nucleate pool boiling of saturated pure liquids at atmospheric pressure is described. A high-speed digital video camera was applied to capture the dynamics of the bubble nucleation process. The liquids used in the study were pure water, ethanol, methanol, acetone and isopropanol. In this article, extensive new experimental data are presented for bubble nucleation site density during saturated pool boiling over a wide range of heat flux. For all test fluids, experimental results show that the bubble nucleation site density increase with increasing boiling heat flux. Also, the results have shown that heat transfer coefficient increase with increasing the nucleation site density. A new model for the prediction of nucleation site density in nucleate boiling is proposed, which predicts the experimental data with an acceptable accuracy.

کلیدواژه ها:

Nucleate Pool Boiling ، Horizontal Cylinder ، Pure liquid ، nucleation site density