How Do You Convert CFM to Thrust?

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SUMMARY

The conversion of Cubic Feet per Minute (CFM) to thrust involves several key formulas. The Mass Flow Rate is calculated as the product of density and volumetric flow rate (CFM). Thrust can be determined using the formula Thrust = (Density) x (CFM^2) / ((Pi) x (r^2)), where r represents the radius of the propeller blade. For a CFM value of 2750, understanding the area calculation, specifically r^2, is crucial for accurate thrust computation.

PREREQUISITES
  • Understanding of basic physics principles, particularly Newton's Second Law of Motion.
  • Familiarity with volumetric flow rates and mass flow rates.
  • Knowledge of geometric calculations, specifically area and radius.
  • Basic understanding of fluid dynamics and density concepts.
NEXT STEPS
  • Study the relationship between density and volumetric flow rates in fluid dynamics.
  • Learn how to calculate thrust using the formula provided, focusing on the area of a circle.
  • Explore the implications of propeller speed and pitch angle on thrust generation.
  • Research practical applications of thrust calculations in aerospace engineering.
USEFUL FOR

Aerospace engineers, mechanical engineers, students in physics or engineering disciplines, and hobbyists involved in propeller design and performance optimization.

addzkebabs
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Hey guys! I'm new to the forums here and was after some help for something that I am currently working on. I need help converting cfm to thrust, i have found the formula though i can't get my head around it.

Here it is:

CFM = Cubic Feet per Minute = Volumetric Flow Rate

Mass Flow Rate = (Density) x (Volumetric Flow Rate)

Newton’s Second Law of Motion: Force = (Mass) x (Acceleration), or F = ma

F = ma = (Mass Flow Rate) x (Velocity), given a constant flow velocity
(i.e., constant propeller speed and pitch angle).

Velocity = (Volumetric Flow Rate) / (Area), where Area = (Pi) x (r^2), the
length of a propeller blade is a good approximation for the radius, r.

Thrust = (Density) x (CFM^2) / ((Pi) x (r^2))


The amount of cfm i need to convert is 2750cfm. Any pointers?

Cheers, Addz.
 
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Ummm... to be a bit more specific I'm having trouble with this segment:

Area = (Pi) x (r^2)

What is r^2?

Although most likely dead simple for you guys, it isn't for me so don't kill me lol! (I'm really new to all of this so thanks)

Cheers, Addz.
 

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