A convenient correlation for heat transfer to constant and variable property fluids in turbulent pipe flow

Abstract

A recent equation for calculating heat-transfer coefficients to constant property fluids in pipes is modified to correlate variable property data. The correlating equation is of convenient form, applies to both liquids and gases, correlates constant property results within 10 per cent for 0·1 < Pr < 10 4 with 10 4 < Re < 10 6 , and correlates variable property data within 20 per cent for 0·7 < Pr < 75 with 10 000 < Re < 506 000. The equation is compared with the Sieder-Tate equation for liquids and the two equations of Petukhov for gases and liquids. Equations for heat transfer to variable property liquid metals are suggested.