# Calculating Wind Turbine Torque - Get the Right Result!

• B
• neonwarrior
In summary, Neonwarrior's windmill has a net torque of 785.4 Nm, which is the same as the author's calculation.
neonwarrior
Hello everyone,

I am reading a book about wind power turbines and found a calculation. I tried it myself and the numbers doesn't match.

Here is an image of the data and result.

I don't get to the same torque.

And also what do you think about the moment of inertia value?

Before the data the author gave the formula:

Hi,

neonwarrior said:
I don't get to the same torque.
I don't get the same torque either. Do we agree on some value ?
 It might just be a simple power of 10 the author 'forgot')

And also what do you think about the moment of inertia value?
Again, what do you get for a reasonable size windmill ?

 The author makes a mess of symbols and dimensions. Uses ##J## for moment of inertia (the 7500 kg/m2) AND for polar moment (m4) .
I find no way to balance dimensions in ##(5-4)##

##\ ##

Last edited:
Hi BvU,

I wasn't aware that there was another moment of inertia (the polar). It's time to read myselft a physics textbook first LOL.

What I get is :

In the first one: converting first the rpm to rad/s

Net torque = J . (DELTA w)/ 5 seconds = 785.4 Nm

And the other question:
I calculated from some papers of windmills a moment of inertia of 113,000 kgm2

Yes, as you said, I think also there is a 10 factor missing or something.

Neonwarrior

neonwarrior said:
Net torque = J . (DELTA w)/ 5 seconds = 785.4 Nm
Same here -- from the given data.

##I## is the symbol of choice for moment of inertia. With three blades times ##{1\over 3} ML^2##, 50 m long wings you would have left over 1 kg of mass for each wing if the total ##I## is 7500 kg m2

These guys mention 12.5 tonne per blade... so more like a factor of 10000 ...

##\ ##

neonwarrior

## 1. How is wind turbine torque calculated?

The torque of a wind turbine is calculated by multiplying the force of the wind on the blades by the distance from the center of rotation to the point where the force is applied. This can be represented by the equation T = F x R, where T is torque, F is force, and R is the distance.

## 2. What factors affect wind turbine torque?

The main factors that affect wind turbine torque include the wind speed, blade length and design, and the angle of attack of the blades. Other factors such as air density, temperature, and altitude can also have an impact on torque.

## 3. How do you ensure accurate torque calculations for a wind turbine?

To ensure accurate torque calculations for a wind turbine, it is important to use precise measurements for wind speed, blade length, and distance from the center of rotation. Additionally, using advanced computer simulations and wind tunnel tests can help in accurately predicting torque.

## 4. What is the importance of calculating wind turbine torque?

Calculating wind turbine torque is important for determining the power output of a wind turbine, which is crucial for the design and operation of the turbine. It also helps in predicting the efficiency and performance of the turbine in different wind conditions.

## 5. Are there any limitations to calculating wind turbine torque?

While calculating wind turbine torque is an important aspect of wind energy technology, there are some limitations. These include variations in wind speed and direction, as well as external factors such as turbulence and gusts, which can affect the accuracy of torque calculations.

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