Deducing safety margin from boiling crisis for arbitrary solid/fluid combinations through the universality of temperature fluctuations

Abstract

Despite decades of research, boiling heat transfer continues to be represented using dimensional quantities (heat flux vs wall superheat relative to liquid saturation temperature). Here, we show that non-dimensional representations of the nucleate boiling regime exist and can be extracted from the temperature fluctuations at different applied heat fluxes. High-speed temperature fluctuations of a platinum wire are measured along the pool boiling curve for a range of test conditions that yield critical heat flux values varying by a factor of five. Motivated by observations of long-term correlations in the fluctuations, we perform a multifractal analysis and show that the Hurst exponent of temperature fluctuations is a non-dimensional quantity that has a universal behavior along the boiling curve for multiple fluids and surface conditions.