Turbulent boundary layer over a flat plate with strong stepwise heating

The turbulent boundary layer over a flat plate with stepwise wall temperature rise from room temperature to 1250 K and free stream velocity of 10.5 m/s was studied. Thermal structures in the heated boundary layer were observed using high speed schlieren cine. Mean and rootmean-square (rms) density distributions were obtained from Rayleigh scattering intensity measurements. Velocity statistics were provided by a single component laser Doppler velocimetry system. Mean and rms velocity profiles, the Reynolds stress, the streamwise and the cross stream turbulent kinetic energy diffusion were determined. Data were collected by a computer based data acquisition and control system. The overall shape of the thermal structures observed in the schlieren pictures of the heated boundary layer is similar to that of the large scale turbulent structures in an isothermal turbulent boundary layer.