Kinematic viscosity and dynamic viscosity are two key parameters that describe fluid viscosity, and they are closely related through a simple formula:‌kinematic viscosity=Dynamic viscosity ÷ density. Let me help you clarify their differences and connections:

1. Different definitions

‌dynamic viscosity(Unit: Pa · s or mPa · s) directly reflects the ability of a fluid to resist flow, and the larger the value, the more "viscous" the fluid is.

‌kinematic viscosity(Unit: m ²/s or mm ²/s) is the ratio of dynamic viscosity to density, which is more suitable for comparing the flow performance of fluids with different densities.

2. Conversion Relationship

The two can be converted to each other through formulas:

Kinematic viscosity（ν) =dynamic viscosity (η) ÷ density (ρ)

Dynamic viscosity（η) =kinematic viscosity (ν) x density (ρ)

3. Application scenarios

‌dynamic viscosityCommonly used in fluid mechanics to analyze flow resistance.

‌kinematic viscosityMore commonly used in engineering, such as evaluating lubricant performance or calculating pipeline pressure drop.

4. Influencing factors

As the temperature increases, the dynamic viscosity of gases and liquids usually increases, but the kinematic viscosity may vary due to changes in density.

Pressure has a significant impact on gas viscosity, especially when the dynamic viscosity increases under high pressure and the kinematic viscosity may decrease.

Simply put, dynamic viscosity isJUE refers to viscosity, while kinematic viscosity refers to relative viscosity, which is more practical in engineering. If you have specific scenarios or data, I can help you further analyze them.