1. What is Water Viscosity?

Dynamic viscosity (μ) is a measure of a fluid's resistance to flow. For water, viscosity decreases as temperature increases. This calculator provides the dynamic viscosity of water at a specified temperature.

2. How Does the Calculator Work?

The calculator uses the Andrade equation:

Where:

• \( \mu \) — Dynamic viscosity (Pa·s)
• \( T \) — Absolute temperature (K)
• \( A \) — 2.414×10⁻⁵ Pa·s
• \( B \) — 247.8 K
• \( C \) — 140 K

Explanation: The equation models the exponential relationship between water viscosity and temperature, with empirically determined constants.

3. Importance of Viscosity Calculation

Details: Water viscosity is critical in fluid dynamics calculations, heat transfer analysis, chemical engineering processes, and biological systems. It affects flow rates, pressure drops, and mixing efficiency.

4. Using the Calculator

Tips: Enter temperature in Kelvin (between 273.15K and 373.15K). The calculator is valid for liquid water in this temperature range.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between dynamic and kinematic viscosity?
A: Dynamic viscosity (μ) is the fluid's resistance to shear flow, while kinematic viscosity (ν) is μ divided by density (ν = μ/ρ).

Q2: Why does viscosity decrease with temperature?
A: Higher temperatures increase molecular motion, reducing intermolecular forces and making the fluid flow more easily.

Q3: How accurate is this calculation?
A: The Andrade equation provides good estimates (±2%) for pure water in the specified temperature range.

Q4: Does this work for seawater or other liquids?
A: No, this calculator is for pure water only. Salinity and other solutes significantly affect viscosity.

Q5: What are typical water viscosity values?
A: At 20°C (293.15K), μ≈1.002×10⁻³ Pa·s. At 100°C (373.15K), μ≈0.282×10⁻³ Pa·s.