Centrifugal force versus gravity (ball on a joint placed on rotating shaft)

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SUMMARY

The discussion focuses on calculating the necessary RPM for a centrifugal control valve, which operates based on the centrifugal force acting on weights attached to a valve shaft. The user seeks to determine the RPM required to achieve a specific angle of the joint holding a ball, which is influenced by the centrifugal force generated by a turbine. The conversation confirms that as the angle approaches 90 degrees, the required RPM tends toward infinity, indicating a critical point in the system's design.

PREREQUISITES
  • Understanding of centrifugal force principles
  • Knowledge of valve mechanics, specifically centrifugal control valves
  • Familiarity with rotational dynamics and RPM calculations
  • Basic physics equations related to angular motion
NEXT STEPS
  • Research centrifugal force calculations in fluid dynamics
  • Explore the design and functionality of centrifugal control valves
  • Study the relationship between RPM and angular displacement in rotating systems
  • Investigate static versus dynamic analysis in mechanical systems
USEFUL FOR

Mechanical engineers, fluid dynamics researchers, and students studying rotational mechanics will benefit from this discussion, particularly those involved in the design and analysis of centrifugal control systems.

LachieD
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Homework Statement



Basically, this is the problem.

[PLAIN]http://img180.imageshack.us/img180/3598/physicsproblem.png

It's related to some design research I'm doing regarding a centrifugal control valve. This is a type of valve that controls the fluid flow based on the centrifugal force that effects the weigths strapped onto the valve shaft. The higher rpm (the shaft is connected to a small turbine powered by the fluid flow), the higher centrifugal force, and the higher the ball should raise (in actual case, connected with the valve disc, but let's ignore that in this ideal case). Now, I'm trying to calculate the neccesary rpm value for a desired angle of the joint holding the ball from vertical line. Ideal system.

Homework Equations



Did I setup the problem correctly? Can this be observed as a static problem as I did? What am I doing wrong? I see if the angle increases toward the value of 90, the neccesary rpm goes into infinity. Is this normal?

Thank you.

The Attempt at a Solution



My attempt is included in the picture.
 
Last edited by a moderator:
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LachieD: If the input units for n are Hz, post 1 currently looks correct.
 
Yeah, that is correct. Thanks. I was just wondering if the problem was setup correctly.
 

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