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Boundary layer in developing channel flow of air is experimentally studied by using the Stereo Particle Image Velocimetry (PIV) technique. The measurement is performed at fixed distance 400 mm from the channel inlet and the Reynolds number (based on the channel length, i.e. the distance from the boundary layer origin) is controlled via the imposed velocity. Re ranges from 8•10 4 to 8•10 5 .The displacement boundary layer thickness δ* varies from 1.7 to 2.5 mm while the momentum one θ from 0.9 to 1.3 mm. It is found, that the critical Reynolds number of transition to turbulence of the boundary layer is lowered by the vicinity of the other perpendicular wall of the square channel; more accurately -it is accelerated by the larger-scale secondary flow, which results into turbulence at slightly lower Reynolds numbers. The laminar-turbulent transition is first apparent on the profiles of the turbulent kinetic energy, later on the velocity profiles. The mechanism might be probably such, that the turbulent flow structures generated in the secondary flow in the corner via Richardson energy transfer mechanism migrate into the laminar boundary layer. While the largescale structures cannot feed from the limited-size boundary layer, the smaller ones can strengthen there.

We studied the grid-generated turbulence by using Particle Image Velocimetry (PIV) technique. We test on this already well studied flow the new ways of analyzing spatially resolved PIV data, such as the spatial spectra and structure functions. We compare some of the turbulence characteristics with results of Laser Doppler Anemometry (LDA).

The paper deals with evaluation of experimental data obtained from the real-size 30 MW output Waste to Energy steam turbine. For many turbine regimes pressures in the last stage area were obtained. At the same time amplitudes of blade tips vibrations were measured of last rotor blades using the blade tip timing system and axial velocity of the steam at the last stage outlet. The obtained data are mutually correlated and relations are analysed between increased vibration values and pressure ratios at the last stage. Increased tip vibrations occur mainly in the area when the pressure ratio over the last blade tip and root is higher than one. In this case there is no expansion, but compression in the last stage of the turbine. The presented results contribute to understanding of processes in the last stage of the steam turbine, mainly for those regimes of turbine operation when its output is lower than 20 % of the nominal output, e.g. during the island regime.