Aerowerx
Well-Known Member
Although it concerns my tailless design project, this is more of a general question, so I am posting it here instead of the "tailless discussion" thread.
If I have a "normal" wing shape, XFLR5 calculates the MAC and the neutral point (for a stability analysis). It does not calculate the static margin, but gives the natural frequencies and damping factors for 8 modes---4 lateral and 4 longitudinal.
Now, on my latest tailless virtual tests, I have extended the center section chord to accommodate the cockpit and engine. Sort of a quasi-BWB design.
In Raymer's "simplified" book, and all the other sources I have seen, they use the reference wing wing area to calculate the MAC. In my current iteration the MAC should be 3.888, but XFLR5 says it is 5.646. This, I think, is resulting in a false indication of the static margin.
Do I need to be concerned about this, so long as the damping factors and natural frequency are reasonable? Or just calculate the MAC manually from the reference wing dimensions?
If I have a "normal" wing shape, XFLR5 calculates the MAC and the neutral point (for a stability analysis). It does not calculate the static margin, but gives the natural frequencies and damping factors for 8 modes---4 lateral and 4 longitudinal.
Now, on my latest tailless virtual tests, I have extended the center section chord to accommodate the cockpit and engine. Sort of a quasi-BWB design.
In Raymer's "simplified" book, and all the other sources I have seen, they use the reference wing wing area to calculate the MAC. In my current iteration the MAC should be 3.888, but XFLR5 says it is 5.646. This, I think, is resulting in a false indication of the static margin.
Do I need to be concerned about this, so long as the damping factors and natural frequency are reasonable? Or just calculate the MAC manually from the reference wing dimensions?
