Determination of the boiling enhancement mechanism caused by surfactant addition to water

In the present investigation, boiling heat transfer coefficients are measured for art electrically heated 390-mu m-dia, platinum wire immersed in saturated water, and in water mixed with three different concentrations of sodium dodecyl sulfate (an anionic surfactant). The addition of a surfactant to water is known to enhance boiling heat transfer. A recently developed photographic/laser-Doppler anemometry measurement technique is used to quantify the vapor volumetric flow rate departing from the wire during the boiling process. The volumetric flow rate data are used to calculate the latent heat and, indirectly, the convection heat transfer mechanisms that constitute the nucleate boiling heat flux Comparisons are made to determine how the heat transfer mechanisms are affected by the surfactant addition, and thus, which mechanism promotes boiling enhancement. The present data are also compared with similar data taken for a 75-mu m-dia wire immersed in saturated FC-72 (a highly wetting liquid) to provide increased insight into the nature of the boiling heat transfer mechanisms.