Heat transfer in turbulent boundary layers subjected to free-stream turbulence - Part II: Analysis and correlation

A new heat transfer correlation for turbulent boundary layers subjected to free-stream turbulence was developed. The new correlation estimates dimensionless heat transfer coefficients without the use of conventional boundary-layer thickness measures and the associated Reynolds numbers. Using only free-stream parameters (mean velocity, turbulence intensity and length scale), the new correlation collected many authors' elevated-turbulence, flat-plate Stanton number data to within t 11%. The level of scatter around the new correlation compared well to previous correlations that require additional flow information as input parameters. For a common subset of data, scatter using earlier correlation methods ranged from 5-10%; scatter around the new correlation varied from 6-9% over the same data subset. A length-scale dependence was identified in a Stanton number previously defined using a near-wall streamwise velocity fluctuation, St'. A new near-wall Stanton number was introduced, this parameter was regarded as a constant in a two-region boundary layer model on which the new correlation is based.