Convection coefficient equations for forced air flow over flat surfaces

In this paper, various comparisons among well-known equations of the convection heat transfer coefficient for forced air flow over flat surfaces and particularly over flat plate solar collectors, with the aim at arriving at a consensus on which of such equations is more accurate are carried out. Through the application of basic principles, various accuracies, inaccuracies and validations of the considered equations have been found and shown, and a consensus reached. Such consensual equation, which comes from the boundary layer theory and takes into account the determining laminar and turbulent flows as well as the wind direction and the decay of the convection coefficient over the surface, also showed close agreement with different experimental works and tends to represent more accurately the actual heat transfer from/to any flat surface submitted to forced convection.

[1]  D. Yogi Goswami,et al.  Principles of Solar Engineering , 1978 .

[2]  D. M. Gates.  Energy Exchange in the Biosphere , 1963 .

[3]  J. Whitelaw,et al.  Convective heat and mass transfer , 1966 .

[4]  A. Johary,et al.  Heat Transfer During Wind Flow over Rectangular Bodies in the Natural Environment , 1981 .

[5]  Peter J. Lunde.  Solar Thermal Engineering , 1982 .

[6]  J.L.A. Francey,et al.  Wind-related heat losses of a flat-plate collector , 1985 .

[7]  Jin Wu,et al.  Wind stress and surface roughness at air‐sea interface , 1969 .

[8]  F. L. Test,et al.  The Effect of Free-Stream Turbulence on Heat Transfer From a Rectangular Prism , 1984 .

[9]  M. Oliphant.  Measurement of wind speed distributions across a solar collector , 1980 .

[10]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[11]  H. Schlichting.  Boundary Layer Theory , 1955 .

[12]  Steve Sharples,et al.  Full-scale measurements of wind-induced convective heat transfer from a roof-mounted flat plate solar collector , 1998 .

[13]  Ernani Sartori,et al.  A critical review on equations employed for the calculation of the evaporation rate from free water surfaces , 2000 .

[14]  R. J. Kind,et al.  Convective Heat Losses From Flat-Plate Solar Collectors in Turbulent Winds , 1983 .

[15]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[16]  W. Beckman,et al.  Solar energy thermal processes , 1974 .

[17]  X. Wang.  An Experimental Study of Mixed, Forced, and Free Convection Heat Transfer From a Horizontal Flat Plate to Air , 1982 .

[18]  Ephraim M Sparrow,et al.  Effect of Finite Width on Heat Transfer and Fluid Flow about an Inclined Rectangular Plate , 1979 .