[Fun_Doge]

Hi,

I am fairly new to CFD and I was thinking about the NS equations used for simulations. One thing that is recommended to do is to non-dimensionalise the equations. As I've understood, you do it to understand where the CFD dimensions are coming from and why we are using them, as well as implementing the non-dimensional form in the source code of the s/w that you are using. Am I right? If so, are there other reason to why we chose to non-dimensionalise it?
Grateful for answers.

[FMDenaro]

Originally Posted by Fun_Doge

Hi,

I am fairly new to CFD and I was thinking about the NS equations used for simulations. One thing that is recommended to do is to non-dimensionalise the equations. As I've understood, you do it to understand where the CFD dimensions are coming from and why we are using them, as well as implementing the non-dimensional form in the source code of the s/w that you are using. Am I right? If so, are there other reason to why we chose to non-dimensionalise it?
Grateful for answers.

I strongly suggest to read a basic textbook of fluid mechanics, you will find the theory. The key is to produce a non-dimensional form of the equation where each term appears as a product of a non-dimensional characteristic number with the non-dimensional physical term of O(1). This way, you can say which effect is more relevant in the flow problem. Hystorically, this way of doing is at the basis of the simplified Euler equations as well as at the basis of the Prandtl theory.

[Fun_Doge]

Thank you for the explanation. Makes sense!