Velocity fluctuations (RMS) in jet axis, 2D vs 3D
 

Hi everyone,

I am simulating a (subsonic) jet impinging on a concave surface and I am interested in RMS values of velocity along the jet axis.

I am using the k-omega SST model so I use the definition of k to find RMS of velocity: sqrt((2/3)*k). I am comparing the results to experimental data and find it quite weird that my results between 2D and 3D don't "differ at all". Does someone know about this?

Let me attach an image illustrating my point. The black curve is the exp data, the blue one is 3D, red one 2D. The x axis is the jet axis, from the nozzle exit (0) to the surface (10)