New Correlative Models for Fully Developed Turbulent Heat and Mass Transfer in Circular and Noncircular Ducts

Abstract

Fully developed turbulent flow in noncircular ducts is examined, and simple models are proposed to predict the friction, heat and mass transfer in most common noncircular channels. It is found that the square root of cross-sectional area is the relatively more appropriate length scale to use in defining the dimensionless parameters to ensure similarity between the circular and most noncircular ducts. By using the dimensionless parameters based on the square root of cross-sectional area, it is demonstrated that the circular tube relations may be applied to most noncircular ducts eliminating large errors in estimation. As turbulent transport phenomena are inherently complex and there, currently, is no extensive experimental data for turbulent heat and mass transfer in noncircular ducts, the simple models are valuable in spite of their limitations.