Calculating Airflow Using Speed, Pipe Diameter: Methods & Formulas for Accurate Results

Is it possible to somehow calculate the amount of air knowing the speed and diameter of the pipe?

Yes
1. Use the distance parameter d (m) from the set speed (m / s)
2.Calculate the volume of air flowing in 1 sec (Pi * r ^ 2 * d)
- where r is half the diameter of the pipe
For the pipe diameter given in meters, we get the flow in m ^ 3 / sec

I'm getting some nonsense
Let us assume that the velocity is 8 m / s

And the diameter of the pipe?

The diameter is 100mm

Within 1 sec, air flows through 8 meters of pipe.
So, its volume:
3.1415 * 0.05 * 0.05 * 8 = 0.0628 m ^ 3
And this is the value of the flow in m ^ 3 / sec
Using the conversion to hours, we get:
226.188 m ^ 3 / hour

Of course!
Everything is correct...
I assumed that the fan does not compress the air and therefore the temperature remains constant

Under typical conditions (domestic ventilation) and for typical measuring instruments (thermoanemometer, damming tube), the accuracy of the air velocity measurement is lower than the error resulting from the lack of temperature and pressure compensation.

Without philosophizing - you multiply the speed by the cross-section - of course you have to in the same units, i.e. for example [m / s] and [m2]
In your case, 8m / s x 0.0079m2 = 0.0632m3 / s
(we multiply by 3600 - the number of seconds per hour)
0.0632m3 / sx 3600s / h = 227m3 / h

I know colleague any56 solved the problem.

>>17764434 And in the case where I have an anemometer in m/s (such a windmill with a display) and to it I have a sealed funnel, which I apply to the anemostat, when calculating m3/h should I give the diameter of the pipe because I have 125 or the diameter of the anemometer itself. In my opinion, the diameter of this windmill on the anemometer.

Pipe radius. We need to make it so that throughout the pipe the flow is laminar and the velocity the same at every point. So you need a sufficiently long straight section, for example, 6xDn.

In the anemostat (plate with airflow around the perimeter), an additional limitation is the minimum allowable diameter of the pipe you apply to the plate. The dn125 pipe is not suitable for measuring from any anemostat, because the flow of air directly on its cylindrical wall causes additional resistance and will most likely disturb (reduce) the flow compared to that which will be without the measuring pipe. A large cardboard box (with an anemometer, for example, mounted centrally in the bottom) instead of a pipe, will be a better idea. It is important to seal the box in the part pressed against the ceiling.

Ok this I understand. I have an anemometer in m/s. Above is an example of calculation with a circle field, I don't know whether to use a windmill circle from an anemometer for calculation.

Cross-section of the opening from which the air exits.