Aerodynamic Structural Noise - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 210

p sat .=.Saturation.vapor.pressure.

The. saturation. vapor. pressure. of. water. at. any. given. temperature. is. the.
vapor.pressure.when.relative.humidity.is.100.percent..A.simpliication.of.the.
regression 2 .used.to.ind.this.can.be.formulated.as:

7 5 . T

T

-
-

2048 625
35 85

.

. p mb ( )

sat = 6.1078 10

. (7.14)

i

.

N O T E :

•. This.will.give.a.result.in.mbar.(millibar),.1.mbar.=.0.001.bar.=.0.1 kPa.
=.100.Pa.
•. p d .is.found.considering.partial.pressure,.resulting.in:

. p d =p - p v . (7.15)

where. p .simply.notes.the.absolute.pressure.in.the.observed.system.
Correlation.vapor.pressure.with.temperature.(Figure 7.9)..Standard.atmo-
sphere:. p 0. =.101325 Pa,. T 0 =.288.15 K,.ρ 0. =.1.225 kg/m³..To.calculate.the.density.
of.air.as.a.function.of.altitude,.one.requires.additional.parameters..They.are.
listed.below,.along.with.their.values.according.to.the.International.Standard.
atmosphere,.using.the.universal.gas.constant.instead.of.the.speciic.one:

•. Sea.level.standard.atmospheric.pressure. p 0 .=.101325.Pa

Pressure & Density Ratio Correlation

15000

10000

5000

0

1 3 5

Density Ratio

7 9 11

Series 1 Series 2 Series 3

FIGURE 7.9
Pressure.and.density.correlation.