Profili - Reggiane fighters
Maecenas vitae congue augue,
nec volutpat risus.
Main menu:
Aircraft > RE2000 > Altre_RE2000
AIRFOILS
Airfoils:
Up to now the wing design is made by the following airfoils:
- Wing root (centerline): Clark YH 16.8%
- Wing tip: Clark YH 7.8%
- Aerodynamic washout: -1.5°
- Structural washout: -0.7°
- Total washout: -0.7 + -1.2 = -2.2°
- Incidence: -0.5° between fuselage axis and flat lower part of airfoil
It has been confirmed by the following drawings:
- drawing A00-1001 of 11.04.40: wing design
- drawing A00-0201 of 20.03.38: aerodynamic model
- drawings A00-1208, A00-1209, A00-1210, A00-1211
- notes of Mr. Pambianchi
Up to now the wing design is made by the following airfoils:
- Wing root (centerline): Clark YH 16.8%
- Wing tip: Clark YH 7.8%
- Aerodynamic washout: -1.5°
- Structural washout: -0.7°
- Total washout: -0.7 + -1.2 = -2.2°
- Incidence: -0.5° between fuselage axis and flat lower part of airfoil
It has been confirmed by the following drawings:
- drawing A00-1001 of 11.04.40: wing design
- drawing A00-0201 of 20.03.38: aerodynamic model
- drawings A00-1208, A00-1209, A00-1210, A00-1211
- notes of Mr. Pambianchi
-----------------------------------------------
Short analysis:
From Mr. Govi's text "Dal Re.2002 al Re.2005" Mr. Longhi stated in a letter "Re.2005 airfoils are the ones used by Airacobra, with a different interpolation. All other Reggiane aicrafts use a modified N38"
The airfoil N38 is described in the report NACA TN-317
From Mr. Govi's text "Dal Re.2002 al Re.2005" Mr. Longhi stated in a letter "Re.2005 airfoils are the ones used by Airacobra, with a different interpolation. All other Reggiane aicrafts use a modified N38"
The airfoil N38 is described in the report NACA TN-317
The airfoil at wing root (not at centerline) is not symmetrical, with a max thickness of about 14.5%.
The leading edge is not sharp.
The trailing edge is reflexed, that means the airfoil is bended upward by a few degrees.
This change is restricting the center of pressure travel, hence reducing the diving moments, having a structural advantage of a more uniform load distribution that leads to a reduced tail size.
The main advantage is actualy the reduced minimum drag coefficient (Cd0) that leads to a higher max speed. The disadvantage is a lower maximum lift coefficient (Clmax).
The airfoil at wing tip has a max. thickness of about 7.8%
Airfoil at wing tip
Airfoil at wing root
It can be easily noticed that the basic N-38
airfoil is different from the airfoils in the Reggiane manuals,
especially according to the following points:
- leading edge at higher position
- trailing edge not reflexed
- thickness
It has recently come out from a Reggiane designer's papers that the airfoil used was the NACA CYH, also known as Clark YH.
- leading edge at higher position
- trailing edge not reflexed
- thickness
It has recently come out from a Reggiane designer's papers that the airfoil used was the NACA CYH, also known as Clark YH.
Airfoil NACA CYH
That airfoil, details in NACA TN-240 and 11.7% thickness, is the classic Clark Y with a reflexed trailing edge.
Reflexed trailing edge of NACA CYH from the Clark Y airfoil (from NACA report)
Going into detail, the wing is developed from the following profiles:
- CLARK YH-9, at 4000 cm from centerline
- CLARK YH-12, at 2500 cm from centerline
- CLARK YH-15, at 1000 cm from centerline
The
aerodynamical features of those airfoils were worked out from wind
tunnel testing in Guidonia, using rectangular wings with single profile
and following setup:
- 0.18x1.08 m
- Aspect ratio=6
- Reynolds nr.=5x10^5- v=42 m/s
- single airfoil
The results were then plotted and extrapolated
