[MachZero]

When sizing a grid for LES studies I understand that best practice is to calculate the integral length scale using RANS variables and then get 5-6 cells within that length scale.

I've been told this is just an approximation. So my question is, how can I verify this? Ive again been told I can calculate tke and dissipation averages but that I need to plug in the formula for those. Can anyone help me in understanding what the formula would be for these variables? And please don't just copy a textbook. What would the formulas be in terms of things I can access in fluent or starccm?

Thanks in advance!

[MachZero]

Any thoughts on this?

[FMDenaro]

Originally Posted by MachZero

When sizing a grid for LES studies I understand that best practice is to calculate the integral length scale using RANS variables and then get 5-6 cells within that length scale.

I've been told this is just an approximation. So my question is, how can I verify this? Ive again been told I can calculate tke and dissipation averages but that I need to plug in the formula for those. Can anyone help me in understanding what the formula would be for these variables? And please don't just copy a textbook. What would the formulas be in terms of things I can access in fluent or starccm?

Thanks in advance!

Your question has a simple answer in a basic textbook of turbulence (e.g. Pope). But as you are not interested to that and your focus is only on a commercial software, you have to post in the dedicated section or read the user guide.