Measuring waterwheel efficiency

In summary: I plan on using a dynamometer to measure the difference in force and distance traveled. Then dividing it by time to get power.
  • #1
rattis
41
0
How did British engineer John Smeaton measure the efficiency of an overshot waterwheel?

I am doing an experiment with overshot waterwheels to find their efficiency, and found that John Smeaton measured their efficiency at about 65%. However I have no idea how he got this number, and I cannot think of an accurate way of calculating its efficiency.

My latest idea is to use a dynamometer to find the difference in forces, then multiply by the distance traveled (2prn (where n is number of revolutions in t seconds, and r is the radius of the axle)) Then divide it all by t; to get Power. This would be compared with a theoretical power output calculated from gravitational and kinetic energy going in.

Is this the correct way to go about this? Or not?
 
Engineering news on Phys.org
  • #2
That's a good question. I couldn't find anything in my research into it. However, I did find a link to a professor at Univ. of Minnesota. She has specifically called out Smeaton and his waterwheel work and she is researching exactly what you are asking about. A link to her page is here:

http://www.me.umn.edu/research/faculty/alexander.shtml [Broken]

THE MEANINGS OF EFFICIENCY is the title of my current book manuscript, analyzing the process by which people transformed the concept of efficiency from a technical measurement in science and engineering into a popular social and cultural value...The first comes from the early industrial revolution, and considers the famous English engineer John Smeaton and his studies of waterwheel performance in the 1750s, for which he received national and international recognition. Although Smeaton did not use the word efficiency, his analysis of waterwheels and power greatly influenced the developing science of mechanical measurement.

Perhaps you could contact her and ask her directly. She has an e-mail link on her page.

From an engineering standpoint, it seems that you are following the basic premise of power out/power into get your efficiency. I think the hard part would be determining the actual power entering the wheel accurately, especially if you are using a natural source like a river.

Hope this helps a bit.
 
Last edited by a moderator:
  • #3
Thanks alot.

Initially i am using a model and the water is flowing down a 'slide' coming from the tap. As the model is not very good the water sprays all over the place, so energy entering and leaving the system is hard to find
 

1. What is waterwheel efficiency?

Waterwheel efficiency is a measure of how well a waterwheel converts the energy of flowing water into mechanical energy. It is expressed as a percentage and can range from 0% (no energy conversion) to 100% (perfect energy conversion).

2. How is waterwheel efficiency calculated?

Waterwheel efficiency is calculated by dividing the actual energy output of the waterwheel by the potential energy of the flowing water. The result is then multiplied by 100 to get a percentage. This calculation takes into account factors such as friction and losses in the system.

3. What factors can affect waterwheel efficiency?

There are several factors that can affect waterwheel efficiency, including the design and size of the waterwheel, the speed and volume of the flowing water, and the materials used in the construction of the waterwheel. Additionally, external factors such as debris or changes in water flow can also impact efficiency.

4. Why is it important to measure waterwheel efficiency?

Measuring waterwheel efficiency is important because it allows us to understand how well the waterwheel is converting energy and if there are any areas for improvement. This information can also help in the design and optimization of future waterwheel systems to maximize energy output.

5. How can waterwheel efficiency be improved?

There are several ways to improve waterwheel efficiency, such as optimizing the design and size of the waterwheel, reducing friction and losses in the system, and maintaining a consistent and optimal flow of water. Regular maintenance and cleaning of the waterwheel can also help improve efficiency over time.

Similar threads

Replies
2
Views
1K
Replies
3
Views
4K
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
1K
Replies
3
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
Replies
11
Views
944
Replies
2
Views
2K
  • General Engineering
Replies
18
Views
2K
Replies
4
Views
2K
Back
Top