Hi there.

When you say you want to write a code, kindly say using which language and are you going to use this code independently or along with any commercial software?

Hello Yahya,

when the problem is turb ulent, there might be very different approches to define vortices. Therfore, i would suggest to "google" lamda-2 or Q-criterion. Both use isosurfaces to visualize vortices.

The determination of the dissipation directly in the field, however, is directly possible.

See e.g. the attached publication.

With an "appropriate" definition of a vortex, you could then integrate the the dissipation inside vortices.  Before that, you could plot your streamlines together with the dissipation field. Use logarithmic scale, since the dissipation might become quite large in the vincinity of walls.  For the dissipation close to the walls, however, you might need a special treatment when wall-functions are employed.

Regards

Bastian

Article How to Determine Losses in a Flow Field: A Paradigm Shift to...

Hey Yahyah,

In answer to the first two parts of your question, many of us use the following reference:

Laurent Graftieaux, Marc Michard and Nathalie Grosjean, “Combining PIV, POD and Vortex Identification algorithms for the study of Unsteady Turbulent Swirling Flows”, Measurement Science and Technology, 12 (2001), 1422-29.

It describes a method to determine the location of the vortex core and the boundaries of the vortex.

In addition, many people like using the "swirl" criterion:

Zhou, J., Adrian, R. J., Balachandar, S. & Kendall, T. M.1999 Mechanisms for generating coherent packets of hairpin vortices in channel flow. J. Fluid Mech.

387, 353–396

Aaron

Dear Yahya,

to be honest I am not a code specialist. Nevertheless, to my knowledge most numerical code have a short come concerning the energy conservation. One has to consider if this might affect your dissipation analysis.

Best regards,

Werner Müller

Dear Yahya,

it would helpful to get more information about your topic, i.e., do you want to performa an instantaneous simulation or the evaluation of a time-averaged flow field such as your attached picture.

Regards

Stephan

Yahya,

I am on the same road. If you wrote the code, can I have the code and use it? Thanks for your assistance

Best