Submitted by bcn0209 (Chris Norman) on Thu, 02/03/2022 - 11:39
Forums:
I'm interested in a discussion on the NLF-0215 airfoil on the Lancair 360 and aerodynamic improvements.
Chris Zavatson has added a reflex of up to -7 degrees to gain 10 knots. I hear the wing extensions will increase cruise speed up to 10 knots above 10K feet.
None if these statements is backed by scientific data other than Chris Zavatson reflex study..
I'd like to find an aerodynamics expert to help a lowly mechanical engineer understand the limitations of the 360's airfoil and what can be done to improve it or at least simulate it in Ansys which I have access to as well as Sumulation Hub.
FWIW, the 235 and 320/360
Submitted by bob mackey on
FWIW, the 235 and 320/360 have reflexed flaps as part of their original design.
The original publications about the NLF-0215 airfoil also include the reflex up to -10 deg and the resulting pressure distributions and drag polars.
https://ntrs.nasa.gov/citations/19830022115
http://www.n91cz.net/Interesting_Technical_Reports/NASA-81-tp1865.pdf
NASA's design goals were to develop a low-drag laminar airfoil in which the lifting capability was not degraded even if the turbulent transition were at the leading edge of the wing. Previous low-drag airfoils had some problems with loss of lift when bugs or other factors reduced the extent of laminar flow.
Chris Z does a lot of great stuff, but he didn't "add the reflex" in this case. He did carefully measure and report the effects of the reflex angle to find the optimum flap positions for use in a Lancair 360.