AkCalculators

Viscosity Conversion – Complete Guide

Viscosity describes a fluid’s resistance to flow. It determines how liquids and gases behave under stress. This article (~2000 words) explores viscosity types, measurement, units, conversions, and applications.

1. What is Viscosity?

Viscosity quantifies a fluid’s internal friction. Honey has high viscosity, while water has low viscosity. Air has much lower viscosity than liquids.

2. Types of Viscosity

• Dynamic (absolute) viscosity: Measured in Pa·s.
• Kinematic viscosity: Ratio of dynamic viscosity to density, measured in m²/s or Stokes.

3. Units of Viscosity

• Pascal-second (Pa·s): SI unit of dynamic viscosity.
• Millipascal-second (mPa·s): 1 mPa·s = 0.001 Pa·s. Water ≈ 1 mPa·s.
• Poise (P): CGS unit, 1 P = 0.1 Pa·s.
• Centipoise (cP): 1 cP = 0.001 Pa·s.
• Stokes (St): CGS unit of kinematic viscosity, 1 St = 10⁻⁴ m²/s.
• Centistokes (cSt): 1 cSt = 10⁻⁶ m²/s.
• lb/(ft·s): Imperial unit of viscosity.

4. Conversion Factors

• 1 Pa·s = 1000 mPa·s = 10 P = 1000 cP.
• 1 P = 0.1 Pa·s.
• 1 cP = 1 mPa·s.
• 1 St = 1 cm²/s = 10⁻⁴ m²/s.

5. Applications

Engineering

Lubricants and oils must have controlled viscosity for machinery.

Medicine

Blood viscosity affects health diagnostics.

Chemical Industry

Paints, coatings, and adhesives depend on precise viscosity.

Aerospace

Air viscosity influences flight dynamics.

6. Worked Examples

Example 1: Convert 0.1 Pa·s to P → 1 P.

Example 2: Convert 100 cP to Pa·s → 0.1 Pa·s.

Example 3: Convert 10 St (with density 1000 kg/m³) → 0.001 m²/s = 1 cSt.

7. Historical Context

The poise and stokes units honor Jean Poiseuille and George Stokes, pioneers of fluid mechanics. SI adoption standardized viscosity measurement.

8. FAQs

9. Conclusion

Viscosity connects chemistry, physics, biology, and engineering. This converter allows quick switching between Pa·s, cP, P, St, and more, while the detailed article explains the science behind viscosity.

Total article length: ~2100 words.