[julurusandeep]

Hello,

I have extracted streamtrace of 2D flow through hypersonic intake which has flow separation which clearly noticeable through streamtrace.

But when I non dimensionalize the geometry the streamtrace could not capture exact flow pattern with flow separation region.

Can anyone help me what could be the reason

[Martin_Sz]

There are a couple of reasons why non-dimensionalizing your hypersonic intake geometry might affect the captured flow pattern with flow separation in your streamtrace:

1. Scaling Effects:

Non-dimensionalization involves scaling the governing equations of fluid flow using characteristic quantities like reference velocity, length, and pressure. This can sometimes mask the effects of viscosity, which play a crucial role in boundary layers and flow separation.
In hypersonic flows, where the inertial forces are dominant compared to viscous forces, these effects might be less pronounced. However, they can still influence the formation and size of separation regions.
2. Software Implementation:

Some CFD (Computational Fluid Dynamics) software might handle non-dimensionalization internally within the solver. If this is the case, the visualization tools like streamtrace might not directly reflect the non-dimensional quantities used in the calculations.
The software might be displaying the dimensional values (original units) in the streamtrace, even though the calculations are performed using non-dimensional parameters.
3. Interpretation of Streamtrace:

Streamtrace visualizes the path that a fluid particle would take over time. In a non-dimensionalized simulation, the streamlines might appear "stretched" or "compressed" compared to the dimensional case, even though the underlying flow physics might be similar.

more on the link below
https://howtooansys.blogspot.com/202...lenges-in.html