inscribecircles()

[inscribecircles()]

Hi Jörg,

 

funny, but you're right. At 90deg it works well now for some reason.

 

I had to search a little bit but here is an example where the problem occurs again. I put the angle to 268 deg and no circles are inscribed. If the angle is set to eg. 275 deg, everything works again as expected.

section_analysis_example_268deg.fdb

 

Cheers

Juryk

[inscribecircles()]

Hi Jörg, 

 

yes, sure. This was meant as a feature request only. It already improved what I had so far and I will rebuild the feature to use the circles as far as possible as it should be more accurate.

 

Anyway, in the above example there seems to be a problem with the inscribed circles if the foil is rotated by 90 deg. Documentation says the curves should be in the XY-Plane. Is there some requirement with respect to orientation too?

 

Cheers

Juryk

[inscribecircles()]

Hi Claus,

 

I was looking only briefly into creating a circle from two tangents and did not really find out how to do this. So, i was happy Mattia mentioned that function. Would it be a problem to extend the functionality and add domain bounds and number of circles or spacing as parameters?

 

 

Attached is a feature for section analysis in which I use the curve parameter to determine the normals. It is assuming that once you found the leading edge, you can move along equal fractions of the two halves to determine thickness and camber. I used the inscribed circles on fractions of the suction and pressure side to determine the leading edge (as the furthest point form the resulting camberline). The result compared to the inscribed circles looks reasonable well, but it is tested with one profile only so far. It works with a uniform parametrization of the curve only (obviously - so the parametrization as input should be removed). 

section_analysis_example.fdb

 

I'd be happy to receive some feedback.

 

[inscribecircles()]

Hi Claus,

 

I actually was looking at the other direction, making the circles go to the very end of the domain. I succeeded bringing the circles much closer to the ends by using imagecurves with a domain of [0.0,0.1]. I can now see why the function is cut off, but I still would appreciate more control over the function as in: used domain of the base curves and number of circles or spacing

 

What exactly is happening towards the leading edge of a profile?

 

I had hoped you could use the function also to determine the leading edge radius of a closed profile and I would like to have the full thickness and camber curves as they could be used for easy variation of thickness and camber along the span of a wing etc. 

 

I also actually wonder, how section analysis is done in xfoil? Is this along similar lines?

 

Cheers

Juryk

[inscribecircles()]

Hallo,

 

starting to use the inscribecircles() function, I am wondering, what determines how close the curve ends are approached? I remember you did intentionally not go to the limits of the curves, but is it possible to control the offset?

 

Thanks

Juryk

[Multiline comments]

Hi Claus, Hi Mattia, 

 

thanks for that. I found the comment/uncomment button and knowing that your code is in C++ I could at least have tried /* */ :_).

 

Cheers

Juryk

[Multiline comments]

Is it possible to create multiline comments as e.g. in python:

 

'''
This is a multiline
comment.
'''

 

Thanks

Juryk