Wind Turbine: A Study to Harness a Energy Source Essay

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Introduction
Following the recent developments in renewable energy sources, wind turbines have been one of the primary devices focussed on. Basically, wind turbines are devices that convert the kinetic energy from the wind into electrical power for human usage. “Wind farms” are created in very windy places to harness this energy.
It is however impossible to harness the entire power potential from the wind. Only 59% of the total kinetic energy of the wind flowing in the turbine can be harnessed. Efficiency greatly depends on the maintenance of the wind turbine and its components.
A variety of tests can be applied to test the material and structures.
In-Depth analysis and NDT tests done.
The lifecycle of wind turbines, the blades are a
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It is usually best to calibrate with a calibration block made from the same material as the real component. Althought this results in higher costs but it gives certainly most reliable results. Open cracks and tight cracks can be separated from each other with eddy current technique.
However a crack which goes through grain boundary is clearly more difficult to estimate. Figure 1 shows eddy current signals from three cracks that were found with dye penetrant testing. a) 3 surface breaking cracks on a turbine blade b) Eddy current signals from cracks.
Fig 1: Eddy current signals from the three cracks shown in the blade .
Measuring the width of a layer is simple with eddy current technique, if there are no strong changes in permeability. In addition, the geometry of a turbine blade can complicate the dimension. Figure 2 shows the width dimension from a first stage X45 vane. The layer was non-conducting material. In this case, the dimension can be easily to carried out with conventional eddy current technique. Fig 2: EC thickness dimension of the layer from a 1. stage vane, material X45 with ceramic layer.
During the lifespan of a material, property can differ severely as displayed in figure 3. In these cases, the solid effect from the permeability can’t be fixed simply. The layer from IN738 turbine blade is impaired. The impaired part gives a similar indicator to ferritic steel. While in the intact area, the measured indication was similar
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