2. turbexp

2. turbexp - WIND TURBINES ENERGY FROM THE WIND Danish Wind...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
WIND TURBINES ENERGY FROM THE WIND The tower must be strong enough to carry the nacelle and rotor and at the same time withstand powerful loads from the wind – in part the force of the wind directly against the tower and in part the force that is transferred from the rotor. We can learn a lot about the loads on a real wind turbine tower by experimenting on tower components made of paper. The wind industry often use destructive material tests where stress on components is increased until they break in order to Fnd the actual strength of each component. 1) Build a lat- tice cube as described in the building instruc- tions. Place the cube on a pair of scales with a stiff board on top. Place the palms of your hands on the board and slowly increase the pressure. Keep an eye on the weight displayed on the scales and note when the cube starts collapsing. Our lattice cube started to collapse at: kg Can you compare this to the load on a real wind turbine tower? 2) Build another lattice cube or repair the one from the previous experi- ment. Place it on a hard surface. Two people press the bottom corners Frmly against the surface. A third person places a string in a tight noose around the top corners. A spring balance (or a dynamo-meter) is used to pull slowly and horizontally at the noose. Our lattice cube started to collapse at: kg Can you compare this to the load on a real wind turbine tower? 3) Build yet an-other lattice cube or repair the one from the previous test. Two sides of the lattice cube are placed on e.g. two chairs and a noose made of string is placed around the cube. A spring balance (or a dynamo- meter) is used to slowly pull on the string. Our lattice cube started to collapse at: kg Can you compare this to the load on a real wind turbine tower? What are the strongest and weakest points of the lattice tower? Why are lattice constructions so strong when the individual bars are weak? ±ind the explanation on http://www.windpower.org/en/tour/ wtrb/tower.htm. TEST THE STRENGTH OF THE TOWER Look up at the Sun. About 4.5 billion years ago an atom cloud in space started to contract, the increase in temperature caused the atom nuclei to melt together to create heavier nuclei – and energy. The result was the Sun. Earth and the other planets were created by matter moving so quickly that it could avoid being attracted to the large amount of matter that was gathering in the Sun. Now – billions of years later we can look up at the Sun 150 million km away and receive its rays of light. EXERCISE 1. The average distance from the Earth to the Sun is 1.4960 · 10 11 m. The speed of light is 2.9979 · 10 8 m/s. Calculate the time in seconds it takes the light from the Sun to reach the Earth. ENERGY CANNOT DISAPPEAR
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/23/2009 for the course CHM 151 taught by Professor Eugene during the Spring '09 term at Wake Tech.

Page1 / 4

2. turbexp - WIND TURBINES ENERGY FROM THE WIND Danish Wind...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online