When a liquid is in contact with a hot surface that is maintained at a temperature greater than the saturation temperature of the liquid, boiling may occur and the heat flux will depend on the difference in temperature between the heated surface and the saturation temperature of the liquid.Even though much of the physics and thermodynamics
of the boiling process is understood, there is much to “see” and “hear” as the temperature difference or the thermal driving force,and/or heat flux, q/A, is increased through an increase in the electrical power input (Walker, 1982). When the heated surface is submerged below the surface of the liquid,the process is referred to as pool boiling. If the temperature of the liquid is below the saturation temperature, the process is called subcooled, or local boiling. However, if the temperature
of the liquid is maintained at the saturation temperature, the process is referred to as saturated, or bulk boiling.