Learning Forum

[sameerkumarverma1105]

Dear all,

I am currently using ANSYS Fluent to model a mucus layer in human lung airways using the Eulerian Wall Film (EWF) model.

I am encountering an issue with film thickness specification and visualization. Although I prescribe different initial film thicknesses (e.g., 25 µm, 300 µm, and 1000 µm), the resulting film height contours appear identical in all cases.

I would sincerely appreciate any guidance or insights on this issue.

Thank you very much.

Regards

Sameer

[Rob]

What does the contour look like? 

[sameerkumarverma1105]

[sameerkumarverma1105]

[sameerkumarverma1105]

The first image corresponds to a film thickness of 1500 µm, while the second represents 25 µm. However, both cases exhibit the same physical thickness, with only the color scale changing between the two images.

[Rob]

Please plot in Fluent. EWF is a wall facet model so only really works when plotted on the walls. 

[sameerkumarverma1105]

The mucus layer is physically present within a finite thickness inside the airway wall, so it should appear in an internal cut plane. Will EWF not work for the plane?

[sameerkumarverma1105]

As suggested, I have also plotted in the fluent but same issue is appearing.

[Rob]

No, EWF is a facet "thin" film model. It has no physical thickness, and shouldn't show on planes other than if there's an image interpolation effect. There's also a numerical cut off for the thickness, but I don't know if you've hit the limiter. 

[sameerkumarverma1105]

I have not reached the limiter value, which is set to 0.005 m by Ansys. If possible, could we have a short online meeting to discuss this issue?

[Rob]

It's not possible - Staff are only able to answer questions and view images on the Forum. Commercial users with the appropriate licences get additional options including calls and our checking models. 

[sameerkumarverma1105]

Since the mucus layer is created using the EWF model, it exists only on the inner wall surfaces and not as a volumetric layer.

[Rob]

Correct.