Qs from Quiz Flashcards
What weather features are commonly associated with high pressure systems?
- Clear skies
- Land breezes
- Light winds
If the wind speed at a location is described by the probability density function, g(U), and the corresponding cumulative distribution function is G(U), then what is the probability that the wind is blowing between 5 and 15 metres per second? I.e. what is P(5<u></u>
G(15) - G(5)
What direction does the wind travel in a High Pressure system?
anticlockwise
The closer the contour lines.. the higher or lower the wind speeds?
higher
closer contour lines => greater pressure difference => higher wind speeds
Which of the following statements is FALSE?
a) The scale factor c changes during vertical translation
b) The area under the curve of a Weibull PDF gives a probability that the wind speed is between certain values
c) The value of a Weibull CDF gives the probability that the wind blows between 0 and a certain speed
d) The value of a Weibull PDF gives the probability that the wind blows at this specific speed
d) The value of a Weibull PDF gives the probability that the wind blows at this specific speed - FALSE
The probability that the wind speed is between cut-in and cut-out speed for a particular wind turbine is 65%. The gross capacity factor of the wind farm will also be 65%.
TRUE or FALSE?
FALSE
b/c spacing losses, transmission losses etc.
Which force component is perpendicular to the v-rel?
a) Lift Force
b) Normal Force
c) Tangential Force
d) Drag Force
a) Lift Force
The Lift force is perpendicular to the v-rel
Which component is NOT considered part of the nacelle?
a) Yawing system
b) Blade hub
c) Control computer
d) Power train
b) Blade hub
The blade hub is NOT considered part of the nacelle
The minimum noise requirement at a nearby park that is 2,000m away is 40 dB. Will the wind farm get a permit if 20m/s is the maximum average wind speed expected at the hub height?
TRUE or FALSE?
TRUE
The angle of attack is the most important angle when trying to determine the lift and drag coefficients.
TRUE or FALSE?
TRUE
What wind system/type is associated with the planetary scale (10s of thousands of km))
Atmospheric circulation e.g. Hadley Cell
What wind system/type is associated with the Synoptic scale (1000s of km)
Low/high pressure system
What wind system/type is associated with the Mesoscale (10s or 100s of km)
Sea breezes
What wind system/type is associated with the Microscale (100s of m)
Turbulence
For what value of ‘a’ do you have maximum power?
a = 1/3
