Heat Transfer in the Oscillating Turbulent Boundary Layer

Measurements of local heat-transfer coefficients in the fully established oscillating turbulent boundary layer over a flat plate are reported. In the range of frequencies from 0.1 to 200 cps and amplitudes from 8 to 92 percent of the freestream mean velocity, increases in local Nusselt numbers of 3 to 5 percent were found. It is concluded that substantial increases in local coefficients, sometimes reported in oscillating flows of low standing wave ratio, may be traced to reduced transition Reynolds numbers.