Monday, July 11, 2011

Homemade Vertical Axis Wind Turbine

1) A section of PVC pipe is used as a test compression bed. Claps hold it securely onto the table. You can also see the brackets which have been drilled and screwed through the plastic to check their strength in holding the PVC under stress.

2) The same compression, just using a piece of wood to distribute force. PVC piping is surprising resistant to bending without using heat.

3) The bent test section of piping attached top and bottom.

4) The same, but different view.

5) Bicycle wheel used as the turbine hub. One side of the inside spoke connections was removed and the bracket holes where drilled through the original bicycle fitting at intervals of three. The size drill bit is the same size as the bracket hole. The size of the brackets themselves limited the number of turbine connections to six. Strings were used to find 60 degree wedges from the central axle point - straight lines were then marked on the outside rim to attach the second turbine bracket fitting.

6) Closer view of the central connectors. The brackets needed to be raised by one nut spacing, due to the curved nature of the bicycle axle-housing. This brought them closer to level.

7) The original bend test section of PVC attached to the wheel, by the interior fixtures only.

8) Different view of the connection.

9) Just the un-touched 60 cm piece of PVC piping, before being heated and bent to make the blades of the turbine.

10) The simple compression platform, comprising of two large pieces of hard wood and 12 bricks. This was needed to hold the hot PVC in place as close to flat as possible while it cooled. Note, the weight of one human was also added to that of the bricks each time after the PVC was heated and slid progressively beneath the top hard wood piece. The final product of this method was uneven, consisting of many 'waves' of plastic.

11) Just heating the uneven waves of plastic that formed as the piece was flattened.

12) Each re-heated section of uneven turbine blade was re-compressed using a smaller piece of wood and bricks, with two human weights added each time.

13) Continuing the time-consuming re-heating/compressing process.

14) Positioned upright, both sides of the blade can be heated.

15) The six completed blades, marked off for cutting to the correct size, in relation to the height of the turbine frame housing uprights. In this case the turbine height was chosen as 68cm, with the flat piece of the blade working out to roughly 24cm in width. For each blade this works out to 1632 square cm of area, meaning 9792 square cm of total space for all six blades.

16) To build the turbine frame, six square pieces of wood were attached to a central hexagon- shaped piece.

17) The square pieces of wood which would hold the uprights, needed screw feeder-holes drilled to make bracket attachment easier. On each of the six pieces, the holes needed to be in the same place, so tracing paper was used once the correct hole placement for the brackets for one upright were chosen. This pattern was then duplicated on all 6 pieces, and then mirrored on the top starfish.

18) Both 'starfish' together, with one completed

19) One side of the uprights attached.

20) The heat-flattened PVC blades attached in their final position forming the six-bladed vertical turbine. The axle is exactly the same diameter as the original bicycle wheel axle, which was used when selecting the turbine axle diameter.

21) Slightly closer view of the assemblage.

22) Different view. One can see the slight bend in the PVC blades. This is in fact well duplicated between each blade, allowing for better uniformity.

The turbine, in it's uncompleted form, can be seen spinning at:

There are several further additions to the design which can be added.

For example, in addition to the electric motor attached to generate electricity, the option of fixing magnets to the top of the turbine exists, and then properly wiring a copper coil configuration above it. This could, hypothetically, generate additional energy, although there may be restrictions to this. Magnet and copper price being one of them.

I am intending to fit outside 'protector blades' to the frame, which will (hopefully) serve the purpose of guiding oncoming wind at only one direction into the turbine cylinder. This avoids the oncoming wind direction opposing one side of the spinning turbine blade each time it rotates back into the wind.

No comments:

Post a Comment