Designing evaporators and industrial reboilers often requires at initial stages of dimensioning (i.e. when the support from a finite element software tool to model the system of interest, isn't yet justified) the use of simple correlations of the boiling process, which is usually done under the assumptions of the pool boiling regime. The available publications, from the elementary grosso modo "advices" of Kern through all succesive authors like Rohsenow, Mostinski, McNelly and Levy (the latter, as far as I know, being only found at Ludwig's Applied Process Design for Chemical Petrochemical Plants), are extremely unreliable in terms of precision, as they can diverge in their predictions of the mean surface heat transfer coefficient by as much as one or two orders of magnitude. This problem is frequently attributed to the complex mechanism of nucleate boiling and the difficulty of modeling it, making the unreliability of correlations an endemic source of uncertainty.
This apparently means that most of current work at the early stages of engineering design of boiling equipment, lacks of a reliable formal framework (even a very low-level one), and it seems to proceed from heuristics and earlier experiences in the field to fine-tuning in numerical simulation software packages, with nothing in between.
Am I wrong with this description of current design process? Are there any currently mainstream correlations (obtained from dimensional analysis or more fundamental physical principles, whatever) which are effective at this intermediate step between heuristics/experience and numerical integration of boiling unit ops.?