Introduction: Tilting at Windmills - Team Flags
This is a turbine concept designed by 4 Glasgow University / Glasgow School of Art Product Design Engineering Students in Year 2 of their course. It is designed to be put on top of buildings to catch updrafting wind. The dimensions are not essential as it was designed to fit into a wind tunnel, if it were to be made for a real building it would be larger and be made from different materials.
Step 1: How to Make the Turbine Blades
To make the blades, 2 square sheets of acrlic were cut each with a slit the same width as the acrylic itself and from the middle of one edge to the centre of the square. This allows the two sheets to fit together. We experimented with different shapes for the blades using foam and once settled on a shape, we made a template from wood and formed the acrylic over the wood to give a nice curve. The photos show a shape cut out of each blade at the end where the motor is mounted, this is so that the blades can spiin around th motor without hitting it.
Once these steps were completed the two pieces were glued together.
For the axle, a square piece of wood with a cross cut on one face, at a depth of half the depth of the piece of wood, was pushed onto each end of the blades. A hole drilled in the centre of each piece of wood allowed us to push a metal rod into each one to act as the axle.
Step 2: Making the Turbine Housing Houseing and Duct
After drawing up several 3D duct designs and running flow simulation on each one, we determined the best shape for the duct and began making the turbine housing and duct as one wooden box.
In the third and fourth pictures you can see the shape of the side walls of the box, the curve is for the duct and the angular part is to house the turbine blades.
In the last 3 photos you can see how we used a thin and flexible piece of wood so that we could screw it on to the curved part of the box and it would bend with the curve to form the duct.
Step 3: Making the Lid for the Housing
The lid for the box was made of two pieces of wood layered on top of each other. This is so that a frame for the clear acrylic window can be made without having to use the router - different sized holes can be cut in each piece of wood to hold the acrylic in place ( as seen in picture 3). After cutting these pieces of wood we cut the piece of acrylic to the right shape and glued it in place with a hot glue gun.
Step 4: Making the Gears and Installing the Motor
Firstly we had to have the side wall of the box routed so that the gears wouldn't stick out further than the rest of the box. The large black gear was drawn on the computer and laser cut to the size we desired, and the centre had the shape of a nut cut into it. This is so that we could glue a nut in the centre of the gear in order to screw it onto the end of the tapped axle.
The motor was not fixed so that we could take it in and out or move it slightly to get the best connection between the gears. As seen in the picture we bolted a rounded piece of wood to the inner wall of the box to keep the motor more secure.
Holes in the side wall of the box were cut for the axles and bearings and also the motor.
Step 5: The Finished Product
With the bearings glued in place, the turbine blades and motor installed, and sufficient washers for spacing and grease so that the blades spin smoothly, the box can be screwed together. If all runs smoothly, up to 19.2V can be produced by this turbine in a wind tunnel!