Rotating motion of a D.C motor

In summary, the conversation revolved around the effects of the number of blades on the output of a turbine. The individual used a D.C motor as a dynamo and observed that more current was produced with two blades compared to one. There was a discussion about finding the optimum number of blades for maximum output and potential ways to analyze the results. The topic of Pelton Wheels was also brought up as a potential resource for further research. The individual was also looking for secondary sources to compare their own results with and improve their project.
  • #1
Advait
8
0
I am doing this project to check how the number of baldes of a turbine affects its output. So I used a D.C motor which can be used as a dynamo. I attached a blade to it and forced water on to it and as a result of the rotation motion of the D.C motor/dynamo current was produced. Then I attached two blades to the motor and noticed that more current was produced. There will be a certain point after which there will be so many blades that their mass will be too much and hence the current would drop. Can anyone tell me how I can find the optimum number of baldes at which the "turbine" will give maximum output current?

Mass of one blade = 4.5 grams
Force of water (flow rate) = 50 ml per sec

And apart from that question above can someone tell me how i can analyse my results the best and draw up a good conclusion?
 
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  • #2
Is there a formula I could use for any calculations?
 
  • #3
There's no way to answer that in a general sense. There's too many things that are particular to your system.

Have you done any research on Pelton Wheels?
 
  • #4
No What are they? What are too many things particular to my system. If that is the case then how can I analyse my results?
 
  • #5
Atleast can anyone give me a link to results for experiments carried out by other people to see the effect of number of blades on the current output? That will help me get secondary research for my project.
 
  • #6
Hi Advait,

you need a mathematical model of your system. This is not a trivial thing to do, because you have to write equations between your observables. For example, you know that the current output 'I' is related to the number of blades, 'N'.
If you plot a graph of I vs N ( I is the y, N is the x) you might be able to guess the equation between I and N. If your theory is correct, you should see a rising I, then a peak and then I falling.

You're in new territory here, just try and get as many data points as you can.
 
  • #7
I already did that. And yes I do get a parabolic graph and I also calculated the equation for that graph using my GDC (TI-84). It seems to work. I mean I get an equation and from that I can find optimum number of blades with maximum output. Thanks.

And now I just need Secondary Sources to compare with my own results as a conclusion to my essay. Can anyone provide me links where someone has stated how many blades they use and what is their output or something like that. For example, tell me if there is any site which tells us the number of blades to the Niagara Dam and its output. Then using my graph and estimating the water flow rate I can theoretically calculate its output and check.
 
  • #8
OK. The theory of turbines and water-wheels looks difficult, as are most things involving fluid flow. I did a google search with 'Turbine theory' and 'water-wheel theory and go a lot of hits.

I can't help further than that, not knowing much about hydrodynamics.
 
  • #10
Yes. I did. but now I just need secondary sources to back up my results. For example if anyone can provide a site where someone has already shown there results to varying number of blades then I could compare my results with his/her and make my project better.
 

1. What is a D.C motor?

A D.C motor is a type of electric motor that operates on direct current (D.C) power. It converts electrical energy into mechanical energy, producing rotational motion.

2. How does a D.C motor rotate?

A D.C motor consists of two main components - a stator (stationary part) and a rotor (rotating part). The stator contains a series of permanent magnets, while the rotor has a set of electromagnets. When an electric current is passed through the electromagnets, they interact with the permanent magnets, causing the rotor to rotate.

3. What factors affect the speed of rotation in a D.C motor?

The speed of rotation in a D.C motor is affected by several factors, including the applied voltage, the strength of the magnetic field, the number of windings in the stator, and the load on the motor. Generally, a higher voltage and stronger magnetic field lead to a faster rotation, while a heavier load can slow down the rotation.

4. Can the direction of rotation in a D.C motor be changed?

Yes, the direction of rotation in a D.C motor can be changed by reversing the polarity of the applied voltage. This can be done by switching the positive and negative terminals of the power source or by using a switch or controller designed for this purpose.

5. What are the applications of D.C motors?

D.C motors have a wide range of applications, including in electric vehicles, industrial machinery, household appliances, robotics, and more. They are also commonly used in fans, pumps, and other devices that require rotational motion.

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