[madakaczka]

Hi

I am simulating a flow over a 2D airfoil with 1m long chord in low turbulent intensity environment using k-omega (SST) model.

From what I was able to find out online is that k-omega turbulence model is a 2 equation turbulence model for which k is the turbulence kinetic energy and omega is the specific turbulence dissipation rate. When calculating the kinetic energy I'm using the following equation:

http://albumizr.com/a/cxRt

where I cam assuming that the turbulent flow in the freestream is isotropic and that my turbulence intensity is 1%. Thus assuming that my freestream flow around the airfoil is at 12.5m/s. I get Turbulent Kinetic Energy of 0.0234375 J/kg. (Correct?)

Now when I want to calculate the Turbulent Dissipation Rate is there a rule of thumb or a similar rule/law which allows you to approximate the Turbulence Length Scale? From previous post on the forum the rule was that your length scale could be anything from 10 to 25% of your chord length.

[sabuj]

For external flow, turbulence intensity (or level) is assumed to be below 1%. I always use 0.5% to be safe.

The way you have calculated turbulence kinetic energy is CORRECT.

I use 10% of the chord length as length scale (assumption only).

Thanks,
LR