Wind function for a sheltered stream

Wind functions are often used to describe the effect of wind on air-water heat or mass transfer when the rate of transfer is controlled by resistance on the air side. Wind functions have been thoroughly studied for large surface areas, but the relationships developed may not apply well to sheltered streams. Wind functions were back-calculated from 47 cases of near steady-state longitudinal temperature profiles in a sheltered stream. Water temperatures were artificially elevated; thus, natural convection was significant. Four formulations often used to predict wind functions were fit to the measurements with roughly equal results. The natural convection term in the formulation by Ryan and Harleman (11) was virtually duplicated by the sheltered stream, while the forced convection term was lower for the sheltered stream, as would be expected.