Reynolds Number

Reynolds Number

### Formula

$$Re=\frac{\rho vd}{\eta}$$

### Terminologies

- Re → Reynolds number.

- ρ → Density of fluid.

- v → Velocity of fluid.

- d → Characteristic length.

- η → Viscosity.

### Conditions / Special Cases

Flow type:

Laminar flow:

$$Re<2000$$

Turbulent flow:

$$Re>4000$$

### Usage

- Used to determine nature of fluid flow.