Unusual results of wings with flaps

[Eric Cheng]

Hi all,

I want to know why there are so  large peaks in the distribution of the lift coefficient in the span direction calculated after the flaps are added. However, under the same flow conditions, it is normal for a single wing (without flap), as shown below:

(png:wing+flaps)

(png:without flaps)

[Rob McDonald]

Is this panel code or VLM?  How did you model the flaps?  Can you provide an example file?  If you tell us more about how you're modeling, we may be able to help provide some best practices.

If you look at the file in the viewer, you'll likely see some hot-spots in that area.  They may or may not be physical or significant.

Rob

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[Eric Cheng]

This was run under the VLM model, and the flaps I set to 30° downward deflection. 

I have posted my *.vsp file.

Thanks a lot.

[Rob McDonald]

I tried looking at this model a bit.

I was unable to get the flaps to deploy to a sensible location by rotating the hinge component -- are you sure you sent me the correct version of the model?

Also, it looks like you have not made any accommodation to cut out the trailing edge of the wing when the flap is deflected.

You should look at the viewer and take a close look at what you are really modeling -- I believe you will find it doesn't make total sense.

Rob