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Abstract

Measurements were made of heat transfer rates and peak heat flux for atmospheric-pressure pool boiling, and of adiabatic and diabatic friction factors, nonboiling and local-boiling heat transfer rates, and burnout heat fluxes for both axial- and twisted-tape swirl-flow forced convection of pure ethylene glycol. Test sections were electrically heated copper, 347 stainless steel, and A-nickel tubes.

Both axial- and swirl-flow friction factors are in good agreement with available generalized correlations. At the higher Reynolds numbers and heat fluxes axial-flow nonboiling heat transfer coefficients show a dependence of Nusselt number on NRe0.98 rather than the traditional NRe0.80. Swirl-flow nonboling heat transfer coefficients from both the glycol data and previously obtained water data are satisfactorily correlated by a single equation. Nucleate-boiling heat transfer coefficients for both ethylene glycol and water fall approximately 50% above Kutateladze's suggested average line. The atmospheric-pressure pool-boiling peak flux is 168,000 Btu/hr. sq. ft. Forced-convection burnout heat fluxes are correlated in a number of ways, including a new additive method which appears to be generally applicable to a large variety of coolants, geometries, and flow conditions.