NDE Digital Methods for Predicting Stiffness and Strength of Wind Turbine Blades - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 193

6.4.5 Experimental Investigation

A. preliminary. estimate. on. the. applications. of. the. different. techniques. for.
nonintrusive.pressure.measurement.systems,.based.on.analysis.references,.
have. approved. the. use. of. the. immersion. acoustic. transducers. speciically.
designed.for.this.purpose.
A. wind. turbine. blade. model. was. designed. using. PSP-active. polymers.
in. a. water. tunnel/channel.. Document. calibration. and. comparable. average.
and. time-accurate. pressures. (kHz). with. pressure. tap. measurement. were.
included.in.the.test.was.performed.any.change.value.of.hydrostatic.pressure.
depend.of.high.elevation.and.frequency.vibration.represents.in.Table 6.16.
Suppose.that.a.light.beam.has.a.wavelength.of.500.nm.in.free.space.and.
then. enters. a. new. medium. where. the. speed. of. light. is. only. 2.00. ×. 10 8 . m/
sec.. (in. vacuum. 3.00. ×. 10 8 m/sec.).. Algorithm. was. correlated. wavelength. λ.
and.hydrostatic.pressure.p.depends.from.some.parameters.illustrated.in.the.
Equation.(6.45):

pRV
Q ij

. λ = . (6.45)

δα

i

Here:
p.is.the.hydrostatic.pressure;
R.is.the.middle.radius.of.the.solid.structure;
V.is.the.velocity.of.light.propagation;
Q ij .is.a.stiffness.constant;
δ.is.the.middle.thickness.of.structure;
α I. is.the.coeficient.of.the.linear.expansion.

Algorithms.were.gotten.from.the.condition.that.is.in.correlation.between.
strength.and.stiffness,.Equation.(6.46)

TABLE 6.16
Change.Value.of.Hydrostatic.Pressure.Depends.on.High.Elevation.and.
Frequency.Vibration
Valueof
Hydrostatic
Pressure,psi/
kg/cm 2

Heightof
Elevation,ft

Frequencyof
Vibration,Hz

Wavelength,
λ ,nm LightColor

14.0/1.0 1.0 1.0 78.3 Blue

58.45/4.13 100.0 100.0 323.0 Blue

102.9/7.26 200.0 200.0 568.0 Green

157.35/10.4 300.0 300.0 813.0 Orange

201.8/13.52 400.0 400.0 1058.0 Black

246.25/16.65 500.0 500.0 1300.0 Black