Reynolds number is one of the most important dimensionless numbers used by Fluid dynamists and CFD Engineers. It is the ratio of inertia force to the viscous force exerted on the fluid elements.
In this video blog, the fundamental principles of the Reynolds number and its application for CFD simulations are explained in detail. Reynolds number is used right from mesh preparation, finding the value of first cell thickness through y+, calculating turbulence intensity, heat transfer coefficient for boundary conditions, finding the value of friction coefficient, scaling, and post-processing/analyzing the CFD results. So, without any doubt, the Reynolds number is the most imperative non-dimensional number for CFD Engineers and fluid dynamists. For more insight watch the full video below.
![\[ \boxed{Re=\frac{\rho V L}{\mu}}\]](https://flowthermolab.com/wp-content/ql-cache/quicklatex.com-57b53d56dcc92937510fdedf436de894_l3.png "Rendered by QuickLaTeX.com")
Here, 
is the density of the fluid, V is the velocity of flow, L is the characteristic length and 
is the dynamic viscosity of fluid.
Watch the full video to know how CFD Engineers use Reynolds number starting from pre-processing to post processing and analysing the results.