Can anyone confirm this equation? Prop. Thrust

  • Thread starter nickpark83
  • Start date
  • Tags
    Thrust
In summary, there are various websites that provide calculations for propeller thrust, but they do not share the formula for it. However, a formula can be found on the NASA website and involves variables such as density, propeller radius, and coefficient of efficiency. When compared to results from other websites, the numbers may differ significantly. Another suggested formula is T=P_{io}^{2/3}(2 \rho A)^{1/3}, where T represents thrust and other variables are defined. It is unclear which formula is correct, but further research may be needed to determine the most accurate one.
  • #1
nickpark83
3
0
can anyone confirm this equation?? Prop. Thrust

there are many websites that calculate propeller Thrust, and they never show any formulas for it... and i somehow manage to find the formula from NASA website, but when i compare the result with each other, i get totally different numbers...

Thrust = (density)(pi)(radius of prop)^2(2)[(2Vk(RPM) + k(RPM^2)]

where k is coefficient of efficiency of prop.
V = speed, V=0 when static

if i just work with the units only, i get the force unit no problem, but the result is way off from the number from websites..
anyone know which one is correct?
 
Engineering news on Phys.org
  • #2
You might want to try this one:

[tex]T=P_{io}^{2/3}(2 \rho A)^{1/3}[/tex] where

[tex]T[/tex] = thrust
[tex]P_{io}[/tex] = (induced) power of the engine
[tex]\rho[/tex] = density
[tex]A[/tex] = propeller area
 
Last edited:
  • #3


As an AI language model, I am not able to confirm the accuracy of this equation. However, based on the information provided, it seems that there may be different factors and variables that could affect the calculation of propeller thrust, leading to different results. It is always best to double-check and verify the equation with reliable sources and experts in the field.
 

1. What is the equation for calculating propeller thrust?

The equation for calculating propeller thrust is: T = ρ * A * V * (V - v), where T is the thrust, ρ is the air density, A is the propeller disk area, V is the velocity of the aircraft, and v is the velocity of the air entering the propeller.

2. How is the equation for propeller thrust derived?

The equation for propeller thrust is derived from the principles of Newton's second law of motion, which states that force is equal to mass times acceleration. In the case of a propeller, the force (thrust) is generated by accelerating a large mass of air through the propeller disk at a high velocity.

3. Can this equation be used for all types of aircraft?

Yes, this equation can be used for all types of aircraft as long as the input variables (air density, propeller disk area, and velocities) are accurately measured or estimated for the specific aircraft.

4. Are there any limitations to this equation?

Yes, there are some limitations to this equation. It assumes that the propeller is operating in a steady state, meaning that the velocity of the air entering the propeller remains constant. It also does not take into account any losses due to friction or other factors.

5. How accurate is this equation in predicting propeller thrust?

The accuracy of this equation depends on the accuracy of the input variables and the conditions under which the propeller is operating. In ideal conditions, the equation can provide a fairly accurate estimate of propeller thrust. However, in real-world situations, there may be other factors that can affect the accuracy of the equation.

Similar threads

  • Mechanical Engineering
Replies
2
Views
2K
  • Mechanical Engineering
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
604
  • Classical Physics
Replies
8
Views
1K
  • Mechanical Engineering
Replies
14
Views
9K
  • Mechanical Engineering
Replies
20
Views
6K
  • Mechanical Engineering
Replies
1
Views
1K
Replies
62
Views
5K
  • Aerospace Engineering
Replies
3
Views
1K
Back
Top