Correlation for CHF at all inclinations in rectangular channels with one side heated

Calculation of CHF (Critical Heat Flux) in rectangular channels with one side heated is needed in applications including nuclear and fusion reactors and cooling of computer chips by boiling liquids. While a well-verified correlation for CHF during horizontal and vertical upflow in such channels is available, there is no well-verified correlation for CHF in other orientations. The present research was done to develop a correlation applicable to all orientations. A new correlation is presented which is in reasonable agreement with data from seven sources. The data include inclinations to the horizontal from 0–316 degree, four fluids (water, R-113, FC-72, and PF-5060), hydraulic equivalent diameter 3.2–23.0 mm, heated equivalent diameter 7.3–281 mm, length to diameter ratio 0.14–83, reduced pressure 0.0045–0.071, mass flux 33–6676 kg/m 2 s, and inlet quality −0.39 to −0.03. The 463 data points from seven experimental studies are predicted with a MAD (Mean Absolute Deviation) of 23.1 %. The same data were also compared to fourteen other correlations. MAD of those correlations ranged from 58 % - 6523 %. The results of this research are presented and discussed. Suggestions are made for further research, including at very low flow rates for which data are not available. • Calculation of CHF for channels in all orientations needed for many applications • A new correlation presented for rectangular channels with one side heated. • Correlation is in good agreement with all data at all flow orientations. • Other correlations have poor agreement with most data. • New correlation to be useful for nuclear & fusion reactors, computers, electronics.