Hello
I have a problem I want to calculate the lifting force of a propeller
Because I want to know what surface area, angle and rotation it must have in order to lift the appropriate weight.
I'm talking about such an arrangement of propellers as in the main rotor of a helicopter
I found such a formula:
http://upload.wikimedia.org/math/0/a/e/0ae45f85f5362024a34386396cd5a802.png
where:
* Pz – generated lift force (kG)
* Cz – lift force coefficient, calculated theoretically for the first time by Zhukovsky, but determined mainly empirically, depending on the angle of attack, but also on the shape of the body.
* ρ – density of a fluid (air at sea level 1.225 kg/m3)(according to the international standard atmosphere – at an altitude of 0 m at +15 degrees Celsius is 0.1249 kG•s2/m4)
* S – wing area (m²)
* V – velocity of the body relative to the fluid (m/s)
example: Assuming that: S=30m2, V=180 km/h (50 m/s), ρ=0.125 kG•s2/m4, Cz=0.7 the lifting force will be 3281 kG.
Now I have questions
How to calculate the "Cz"?
The result gives as much as these propellers will carry?
And where is given the propeller's contour after all, it also depends on it.
Or unless this is not the formula is supposed to be.
Please answer.
I have a problem I want to calculate the lifting force of a propeller
Because I want to know what surface area, angle and rotation it must have in order to lift the appropriate weight.
I'm talking about such an arrangement of propellers as in the main rotor of a helicopter
I found such a formula:
http://upload.wikimedia.org/math/0/a/e/0ae45f85f5362024a34386396cd5a802.png
where:
* Pz – generated lift force (kG)
* Cz – lift force coefficient, calculated theoretically for the first time by Zhukovsky, but determined mainly empirically, depending on the angle of attack, but also on the shape of the body.
* ρ – density of a fluid (air at sea level 1.225 kg/m3)(according to the international standard atmosphere – at an altitude of 0 m at +15 degrees Celsius is 0.1249 kG•s2/m4)
* S – wing area (m²)
* V – velocity of the body relative to the fluid (m/s)
example: Assuming that: S=30m2, V=180 km/h (50 m/s), ρ=0.125 kG•s2/m4, Cz=0.7 the lifting force will be 3281 kG.
Now I have questions
How to calculate the "Cz"?
The result gives as much as these propellers will carry?
And where is given the propeller's contour after all, it also depends on it.
Or unless this is not the formula is supposed to be.
Please answer.
Of course you can convert rpm to average rotor blade speed
