• turbulence generator
• low pressure turbine
• wind tunnel
• hot wire anemometry
• length scales
• turbulence
• turbomachinery

The main objective of this thesis is to characterize the incoming flow to the low-pressure blade cascade installed in the C1 facility, a low-speed wind tunnel with atmospheric discharge located at the von Karman Institute. This work is part of a broader project aimed at characterizing blade losses under varying levels of inlet turbulence. To achieve this goal, it was necessary to characterize the incoming flow and to have the capability to vary its turbulent characteristics through an active turbulence grid.
The key parameters of interest for turbulent flow characterization are turbulence intensity and integral scale. During this campaign, these are evaluated using the thermal anemometry measurement technique, fundamental in the study of turbulent flows in turbomachinery applications.
To achieve the set objective, it was necessary to design and construct a turbulence grid capable of varying the inlet conditions. This grid had to be able to slide along the lower plane of the tunnel and inject a variable amount of air into the flow through small holes drilled on cylindrical bars. A characterization of this grid was conducted to correlate the imposed pressure difference with the processed flow rate, thus allowing the evaluation of a dimensionless injection ratio. Subsequently, the experimental campaign started, during which we observed a wider range of intensity and integral scale achievable with this grid compared to a simple passive grid, where this two parameters are constrained to each other and solely to the grid's position relative to the measurement plane.