Created By : Naaz Fatima

Reviewed By : Phani Ponnapalli

Last Updated : May 18, 2023

The Reynolds Number Calculator is a simple tool that determines the flow pattern for various liquid flow scenarios. that Simply enters data into the calculator's input boxes and presses the calculate button to get the Raynolds number of a liquid.

Choose a Calculation
Fluid density (ρ)
Fluid velocity (u)
characteristic linear dimension (L)
Dynamic viscosity (μ)

What is Meant by Reynolds Number?

The Reynolds number (Re) is a dimensionless variable in physics that is used to determine the flow patterns of fluids. It is mostly employed in the field of fluid mechanics. It assesses whether fluid is flowing in a laminar or turbulent pattern. The flow of liquid is laminar if the Reynolds number is less than 2000. The fluid flow is turbulent if the Reynolds number is larger than 4000. Force is the formula for calculating the Reynolds number.

Reynolds Number = Inertial Force/ Viscous

The product of velocity, density, and length divided by the viscosity coefficient is Re. Re = (ρ * u * L)/μ or Re = (u * L)/v

  • Where, Re = Reynolds number
  • ρ = density of the fluid
  • u = fluid velocity
  • L = characteristic linear dimension
  • μ = dynamic viscosity of the fluid
  • v = fluid kinematic viscosity (v = μ/ρ)

How to Calculate Reynolds Number?

The following is a step-by-step technique for calculating the fluid's Reynolds number. Use these tips to answer the questions quickly and easily.

  • Step 1: Make a note of the information provided in the question.
  • Step 2:Multiply the density, velocity, and characteristic linear dimension of the fluid.
  • Step 3:The Reynolds number is calculated by dividing the product by the dynamic viscosity.
  • Step 4: Although, multiply the fluid's velocity by the characteristic linear dimension.
  • Step 5:To get the Reynolds number, divide the result by the fluid's kinematic viscosity.

For more concepts check out to get quick answers by using this free tool.

How to Use the Reynolds Number Calculator?

The Reynolds number calculator is used in the following manner

  • Step 1: Fill out the input fields with the density, viscosity, and diameter values.
  • Step 2: To get the value, click on the "Submit" button.
  • Step 3: Finally, in the new window, the Reynolds number for the inputs will be presented.

The roughness coefficient is determined by the pipe's material. The values for various pipes are listed below. The ratio of the pipe's area and perimeter is known as hydraulic radius.

Hydraulic radius R = A/P = πr²/2πr = r/2 = d/4

Divide the pipe length by the drop to get the slope of the energy line. The flow discharge Q is calculated using the following formula Q = AV

FAQs on Reynolds Number Calculator

1. What role does Reynolds Number play?

The Reynolds number can be used to forecast flow patterns in a variety of fluid flow scenarios. The lower the Reynolds number, the more laminar the flow is, and the higher the Reynolds number, the more turbulent the flow is.

2. What is the formula for calculating Reynolds Number?

Inertial force/viscous force, or ρuL/, is the formula for calculating Reynolds number. To check the Reynolds number, enter the values into the formula and run the processes.

3. What exactly is a turbulent flow?

When Re > 3000, turbulent flow is frequently used. It is characterised by chaotic eddies and other flow instabilities and is governed by inertial forces.

4. What exactly is laminar flow?

When viscous forces are dominant, laminar flow occurs, which is characterised by smooth and steady fluid motion. Laminar flow has a Reynolds number of Re 2100.

5. What is the Reynolds Number and how is it calculated?

A flowing fluid's Reynolds number (Re) is derived by multiplying the fluid velocity by the internal pipe diameter (to obtain the fluid's inertia force) and then dividing the result by the kinematic viscosity (viscous force per unit length).

6. What is Water's Reynolds Number?

Tap water has a velocity of around u = 1.7 m/s. We choose (as a material) water at 10 °C in our Reynolds number calculator and get Reynolds number Re = 32 483.