An experimental examination of turbulent flows in a boundary layer with an inversion of the parietal heat flux

Gravitational effects on boundary layer structures encountering an upstream heated flat wall oriented parallel to the flow was examined in a wind tunnel. Particular attention was given to the heat and mass transfer within the developing internal boundary layer above the wall. An electrically heated flat plate was employed as the wall, providing an apparatus to test flows moving over surfaces of different temperatures. Velocities were ascertained by pitot tubes and hot-wire anemometry, temperatures by platinum-coated resistance sensors, and mass transfer by injecting an aerosol into the channel for collection by particle analyzers at strategic points. The results are considered significant for the diffusion of a pollution plume in the presence of a sea breeze, and indicate the presence of three layers above the heated plate. An unstable upstream flow was determined to remain unstable downstream of the plate.