Toms Wheel - results
Toms Wheel - Results
The paddle was fitted with a brake attached to an arm with weighing scales at the end of the arm. By applying different forces to the brake, different torques could be applied which could be measured via the weighing scales.
The small fixed sprocket at the centre was attached to a moveable arm, so that the angle of the paddles could be varied.
The waterwheel was attached to the side of a boat and dragged through the water.
The following table shows the results of having the paddles offset by 12.5 degrees, and gradually increasing the braking:
| Weight (kg) | Waterwheel rpm | Water speed (m/s) | Power (W) | Efficiency |
| 4.5 | 13 | 0.95 | 31 | 0.16 |
| 6.8 | 11 | 0.95 | 40 | 0.20 |
| 9.1 | 8.75 | 0.85 | 42 | 0.30 |
| 11.4 | 6 | 0.8 | 36 | 0.30 |
When the waterwheel was being dragged alongside the boat, and the same torque was appled, then the speeds were comparable, so the different paddle angles can be compared:
| Paddle Angle (degrees) | Power |
| 0 | 23 |
| 9.5 | 42 |
| 11 | 43 |
| 12.5 | 42 |
| 14 | 37 |
| 16 | 35 |
So it would seem that the maximum power is achievable at the paddles being offset by 11 degrees. It is worth noting that as the torque on the waterwheel increases, the bow on the floats drops deeper into the water, effecting the angle of the paddles. With an increase in torque, 12.5 degrees offset was found to be more efficient.