STUDY OF FORCES ACTING ON A HEATED SURFACE N NUCLEATE BOILING AT HIGH HEAT FLUXES.

Report on a heated surface of about 15-mm diam, suspended in a saturated water at atmospheric pressure; a balance was employed to measure the varition of buoyant force due to boiling, and thereby the mean vapor pressure within a vapor mass growing on the heated surface was obtained. High-speed photography was also used to observe the growing behavior of each vapor mass. A theoretical analysis of the vapor pressure of vapor masses agrees well with the experimental results and suggests that the growth of vapor is governed strongky by the gravitational effects of vapor. The lower limit of the region of high heat fluxes n nucleate boiling was analyzed yielding good agreemenwiththe experimental results. A discussion of burn-out is also presented.