On the effect of moving blade grid on the flow field characteristics

On the effect of moving blade grid on the flow field characteristics

Blog Article

The motivation of this paper is the continual development of the blades for the last stage of the steam turbine.The biggest problem is the slenderness of such blades and the extreme sensitivity to aeroelastic vibrations (flutter) caused by the instabilities present in the flow.This experimental research is dealing with the aeroelastic binding click here of the moving blades located in the blade grid with the flow field and vice versa.A parallelogram is used to ensure one order of freedom of the blade.The grid has five blades in total, three of them are driven by force control using three shakers.

The deviation as well as force response is measured by strain gauges and dynamometers.The flow field statistical as well as dynamical characteristics are measured by optical method Particle Image Velocimetry.The grid nitrile gloves in a bucket is connected to the blow-down wind tunnel with velocity range up to 40 m/s.The aeroelastic binding is investigated in dependency on used actuation frequency and maximal amplitude (the intensity of force actuation) and on different Reynolds numbers.The flow field and the wake behind each individual blade are studied and the maximal interaction is examined for individual inter-blade phase angle of the grid.