[Mr.Zaater]

I am simulating a turbulent flow around an airfoil at Re = 6e+6 and Ma = 0.7 and I chose the turbulence model to be kOmega

I have several questions about the pre-processing part

1. What is the difference between nu and nut? and What property is needed in "0" file?

2. How to let OpenFOAM understand the Re? (How to enter Re into OpenFOAM)?

3. How to calculate "Omega"?

4. How to calculate "k"?

[Alczem]

Hey

1. What is the difference between nu and nut? and What property is needed in "0" file?

nu is the kinematic viscosity that should be used in transportProperties (assuming you use simpleFoam for instance) and nut is the turbulent viscosity, which is used in the 0 folder.

2. How to let OpenFOAM understand the Re? (How to enter Re into OpenFOAM)?

OpenFoam does not need to understand the Re, your boudary conditions will dictate it (your inlet velocity, your airfoil etc).

3. How to calculate "Omega"?

4. How to calculate "k"?

If you look around in the OpenFoam doc and online, you will find formulas to calculate the initial values depending on your fluid and your conditions. There is this online calculator if you want to compare values:


http://ichrome.com/blogs/archives/342


Good luck! And search the forum too, you will find better and more complete answers than mine