Terence Fields asked 4 months ago
I was wondering if you could give some specific details about how you implement the Trefftz plane analysis when reflections are present due to free-surface/ground-effect. Firstly, I’m interested to know how you integrate the influence of trailing vorticity in the wake? Do you have some references which illustrate your preferred approach? Second, when a reflection plane is present, is it just a case of including the reflected wake elements in the Trefftz integration? In the case of an aircraft travelling forwards with some small velocity component towards or away from the ground, the inflow-aligned wake would be diverging away or converging towards the ground plane; in this case would you enforce the wake elements to be parallel with the ground? Or is it acceptable that your wake and reflected wake elements might not be perpendicular to the trefftz plane?
techwinder Staff answered 4 months ago
Hello,
The wake is implemented in the same way as the mirror plane panels and the wake panels are aligned with the x-axis.
It is done in the same way in flow5 and xflr5. See for instance
PanelAnalysis::getDoubletInfluence(...)
in this class
https://sourceforge.net/p/xflr5/code/HEAD/tree/trunk/xflr5/xflr5v6/xflanalysis/plane_analysis/panelanalysis.cpp#l1874
The analysis does not consider either horizontal and vertical plane motion, but only the angle of attack.
André