Topics relate to Fluent, CFX, Turbogrid and more

Physical Meaning of the value in the Eddy viscosity

    • skdubey

      Hi All,

      I just have few basic question, I just created the line in the post-cfd and insert the chart where I try to plot the data such as pressure, velocity and other. 

      A. One thing I was unsure about was whether there were eddy formations, which visually appeared to be absent when I viewed the results in contour mode. However, when I plotted the values, I expected them to be very low, but I obtained values on the order of 10^-1 to 10^-2, whereas in the contour plot, the values were around 10^-18. I am a bit surprised to see this difference.

      B. As the value of the eddy viscosity changes over the length scale, a large value indicates a large number of eddies, while a small value indicates a small number of eddies. When it comes to dissipation, does low eddy viscosity result in low dissipation, and high eddy viscosity result in high dissipation?


    • Federico Alzamora Previtali


      A) What are you plotting here? Are you sure you have the same scales for both plots?

      B) In general yes, low eddy viscosity means lower number of eddies, which results in low dissipation since there is less turbulence and mixing occuring, which in turn means less energy to dissipate (vice versa for high eddy viscosity).

Viewing 1 reply thread
  • You must be logged in to reply to this topic.