Final windmill
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Transcript of Final windmill
Windmill
GROUP MEMBERS◦DANIAL KAYANI (130238)◦HADIA TAYYAB (130276)
HOW WINDMILL WORKS:◦Windmill converts kinetic energy of wind to mechanical energy.◦Which then in turn converted into electrical energy by connecting windmill to the generator.
TYPESHORIZONTAL AXIS WIND TURBINE (HAWT)Have blades that rotates about horizontal axis parallel to wind.1-Multiblade type2-Sail type3-Propeller type
VERTICAL AXIS WIND TURBINE (VAWT)Have blades which rotates about vertical axis1-Savanious type2-Darrieus type
HAWT vs VAWT
Multiblade type
◦Has more number of blades usually 12-20.◦Blades made of sheet metal or aluminum.◦The width of plate increases from center to periphery.◦The diameter of rotor ranges from 2-5m.◦Low cost and used normally for pumping water.◦Speed about 60 to 80 rpm.
Sail type◦Blade surface is made of cloth or plastics arranged in mast and poles or sail wings.◦Runs at low speed about 60-80 rpm.
Propeller type◦Turbine blades are shaped a
lot like airplane wings -- they use an airfoil design. In an airfoil, one surface of the blade is somewhat rounded, while the other is relatively flat.
◦When wind travels over the rounded, downwind face of the blade, it has to move faster to reach the end of the blade in time to meet the wind travelling over the flat, upwind face of the blade
◦Run at 300-400 rpm
Savanious type◦The savanious turbine is s-
shaped if viewed from above.◦ It is relatively slow but yields
high torque.◦ It consists of hollow circular
cylinder sliced in half, the two halves fixed to vertical axis.
◦Wind exert force greater fore on cupped face than round face.
◦The turbine rotates due to pressure difference between cupped face and round face.
◦Efficient design but requires large surface area.
Darrieus type◦Darrieus type looks like an egg beater and has two to three blades shaped like an aero foil
◦The fixed pitch blades are curved an attached to hubs on vertical shaft at both ends.
◦The curved blade has shape like the rope during skipping.
◦It requires less surface area.
HAWT◦HAWT have all there drive train equipment located in
nacelle.◦Rotors must be oriented so that blades are aligned with
wind.◦HAWT are placed on high towers to access stronger winds at greater heights.
◦Propeller are most common type of HAWT.
◦Small wind turbine use tail fin to align rotor with wind
direction. ◦In modern turbines there is
yaw control system.
VAWT◦VAWT have all their
drive train on the ground
◦Blades do not require orientation with respect to wind.
◦They cannot readily be placed on high towers
to exploit greater heights.
◦Darrieus are most common type of VAWT.
Wind turbines◦Few watts to 2.5MW◦2 to 6 blades◦17.5 rpm to 30 rpm for 2MW◦40 rpm to 60 rpm for 40KW t0 200KW◦Blade diameter ranges from 3.65m to 90m depending on capacity
◦Material used for blades• Canvas• Wood• Aluminum• Reinforced fiber• steel