• pitched-blade turbine
• trailing vortice

This thesis describes an experimental investigation of the flow in a vessel stirred by a PBT (Pitch Blade Turbine) with blades inclined at 45◦. Full 3 dimensional phase resolved measurement of velocity and vorticity fields and turbulence level were obtained with a Laser Doppler Anemometer (LDA) at Re= 1200. The working fluid has a mixture of Glycerol (80%) and (20%)
still water which as a Dynamic Viscosity is 60.1 [mPa s] at 20 degree of temperature (more or less 1◦C) both impeller diameter (D) and clearance
(C) were set to T/2. In the present work cylindrical coordinate have been used. The result
show gradient of flow velocity, kinetic energy and the vorticity by means of plots in the planes (:z), (r:z), (r:). A very fine mesh with a step of 0.0066 D was used over a range 0.3095 < z
T < 0.5616, 0.1522 < r T < 0.3120 with
0◦ <  < 90◦. 3600 point were taken in 3452,1 mm2. The vortex start behind of each blades with a diameter dstart = −−−−−−− in 0.00—r t relative to the rotation impeller axis and was inclined at 20 degree to the horizontal plane. The vortex finish after 135 degree behind the blade with a diameter dfinish = −−−−−−− in 0.00—r t and 0.00—z
t . The Kinetic Energy level of turbulence has the max high in point −−−−−− r t and −−−z t . The Kinetic Energy level of turbulence decay to nearly uniform and low values outside the region.———————-
The data accurately identify flow regions where intense turbulence is
present and thus give useful indication for the optimization of mixing processes.