# Euler Number in Fluid Mechanics

**Formula:**`Re = ρvd/μ`

## Introduction to Euler Number in Fluid Mechanics

The Euler Number (Re) in fluid mechanics is a dimensionless quantity that represents the ratio of inertial forces to viscous forces within a fluid flow. It plays a crucial role in determining the flow regime of a fluid.

The formula for calculating the Euler Number is given by: `Re = ρvd/μ`

, where `Re`

is the Euler Number, `ρ`

is the fluid density, `v`

is the fluid velocity, `d`

is the characteristic length, and `μ`

is the kinematic viscosity of the fluid.

## Parameter usage:

`velocity`

= fluid velocity`characteristicLength`

= characteristic length`kinematicViscosity`

= kinematic viscosity

## Output:

`Re`

= Euler Number

## Data validation

The inputs for velocity, characteristic length, and kinematic viscosity should be positive numbers.

## Summary

This formula enables the calculation of the Euler Number, which provides critical insights into the flow characteristics of a fluid in various engineering applications, such as pipe flow, aerodynamics, and heat transfer.

Tags: Fluid Mechanics, Euler Number, Dimensionless Quantity, Viscous Forces