Forster-Zuber equation, boiling

The correlation given by Forster and Zuber (1955) can be used to estimate pool boiling coefficients, in the absence of experimental data. Their equation can be written in the form ... 

In the limiting case of S = F = 1, this equation converts into that for saturated boiling, (4.156). The heat transfer coefficients aB for nucleate boiling in free flow were taken by Chen from an equation from Forster and Zuber [4.93]. More recent investigations [4.94], etc. showed however, that this gives somewhat inaccurate results. It therefore seems more sensible to calculate aB using one of the formulae from section 4.2.6. 

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