1. What is Kinematic Viscosity?

Kinematic viscosity is a measure of a fluid's internal resistance to flow under gravitational forces. It is the ratio of dynamic viscosity (μ) to density (ρ) of the fluid. For water, it's particularly important in fluid dynamics and engineering applications.

2. How Does the Calculator Work?

The calculator uses the kinematic viscosity equation:

Where:

• \( \nu \) — Kinematic viscosity (m²/s)
• \( \mu \) — Dynamic viscosity (Pa·s)
• \( \rho \) — Density (kg/m³)

Explanation: The equation shows that kinematic viscosity decreases with increasing density when dynamic viscosity remains constant.

3. Importance of Kinematic Viscosity

Details: Kinematic viscosity is crucial in determining Reynolds number, analyzing flow regimes, and designing fluid systems. It's particularly important in hydraulic engineering and lubrication applications.

4. Using the Calculator

Tips: Enter dynamic viscosity in Pascal-seconds (Pa·s) and density in kg/m³. Typical values for water at 20°C are μ = 0.001002 Pa·s and ρ = 998 kg/m³.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between dynamic and kinematic viscosity?
A: Dynamic viscosity measures resistance to flow, while kinematic viscosity incorporates density and relates to flow under gravity.

Q2: What are typical kinematic viscosity values for water?
A: At 20°C, water has ν ≈ 1.004 × 10⁻⁶ m²/s. It decreases with temperature.

Q3: Why is kinematic viscosity important in fluid mechanics?
A: It appears in dimensionless numbers like Reynolds number that characterize flow regimes.

Q4: How does temperature affect kinematic viscosity of water?
A: As temperature increases, kinematic viscosity decreases because viscosity decreases faster than density.

Q5: What units are used for kinematic viscosity?
A: SI units are m²/s, but Stokes (St) and centistokes (cSt) are also common (1 m²/s = 10⁴ St = 10⁶ cSt).