# Reynolds Number Calculator, Calculation of Re With Example

### Reynolds Number Calculator:

Reynolds number has wide applications in real life. It can describe fluid flow in a pipe, flow around airfoils, or an object moving in a fluid. In the following text, we present the Reynolds number equation, a discussion of units, and a comparison of laminar and turbulent flows.

Read on to know what Reynolds numbers are for laminar flow and turbulent flow.

You can also find some examples of calculations that can be done with the Reynolds number formula using this calculator.

• Multiply fluid density, fluid velocity and characteristic linear dimension.
• Divide the product by the dynamic viscosity to get the Reynolds number.
• Otherwise, increase the velocity of the fluid along the characteristic linear dimension.
• Divide the result by the kinematic viscosity of the fluid to get the Reynolds number.

### Reynolds Number Formula:

Reynolds number Re is equal to the density of the fluid p (kg /m3) in kilogram per meter3 and multiply the fluid velocity u (m) in meter and multiply the characteristic linear dimension L(m) in meter and divided by the  dynamic viscosity of the μ (Ns/m2) in Newton per meter2.Hence the Reynolds number can be written as

Re=(p (kg /m3)*u (m)*L(m))/ μ (Ns/m2)

or Re=(u*L)/V

Where

Re= is the Reynolds number

P=is the density of the fluid

U=is the fluid velocity

L=is the characteristic linear dimension

μ =is the dynamic viscosity of the fluid

V=is the fluid kinematic viscosity (V= μ/p)

### Example:1

Find the Reynolds number,if the fluid has viscosity o.4

Ns/m2 and relative density of 250 kg /m3 through a pipe of 25mm with a velocity of 4m

Given that

Viscosity of the fluid μ=0.4 Ns/m2

Fluid density ρ=250 kg /m3

Diameter of the fluid L=25*10-3 m

Fluid velocity u=4m

Reynolds number formula is

Re=( ρ*u*L)/ μ

Re=(250*4*25*10-3)/0.4

Re=62.5

Therefore, Reynolds number of the fluid is 62.5 and the flow of the fluid is laminar flow

### Example:2

Find the Reynolds number,if the fluid has viscosity o.6

Ns/m2 and relative density of 800 kg /m3 through a pipe of 15mm with a velocity of 2m

Given that

Viscosity of the fluid μ=0.6 Ns/m2

Fluid density ρ=800kg /m3

Diameter of the fluid L=15*10-3 m

Fluid velocity u=2m

Reynolds number formula is

Re=( ρ*u*L)/ μ

Re=(800*2*15*10-3)/0.6

Re=40

Therefore, Reynolds number of the fluid is 40and the flow of the fluid is laminar flow