What is G-Force (RCF)?

G-force, or Relative Centrifugal Force (RCF), is a measure of the centripetal acceleration experienced by an object in circular motion, expressed as a multiple of Earth's gravitational acceleration (g = 9.81 m/s2).

• 1 G = Normal Earth gravity
• 10 G = 10 times gravitational pull
• 10,000 G = Typical centrifuge separation

Higher G-forces cause denser materials to separate faster from lighter materials - the basis of centrifugal separation.

Key Formulas

Applications by G-Force Range

• 1-10 G: Vibrating screens, shale shakers (4-8 G), washing machines
• 100-500 G: Cream separators, industrial settling
• 1,000-4,000 G: Decanter centrifuges, oil-water separation
• 5,000-15,000 G: Disc stack separators, clarifiers
• 10,000-100,000 G: Laboratory centrifuges
• 100,000+ G: Ultracentrifuges for molecular separation

Design Considerations

• Tip velocity: Should typically stay below 150-200 m/s for steel rotors
• Rotor stress: Increases with square of velocity - material limits matter
• Balancing: Critical at high RPM - dynamic balancing required above 3,000 RPM
• Bearings: Precision bearings needed for high-speed applications
• Critical speed: Avoid operating near natural frequencies of the rotor

Radius Measurement

For centrifuges, measure the radius from the axis of rotation to the point of interest (usually the maximum radius where separation occurs).