Rotary flap

Abstract

A rotary flap is liable to turn about a longitudinal axis of rotation defined according to the first span of the flap, the flap having a profile extending along the chord and including a first leading edge, a first trailing edge, an inner surface and an outer surface. The inner surface and outer surface have non-concave shapes. The first leading edge has a rounded shape provided with a curve radius more or less constant or elliptical in shape whose first major axis to minor axis quotient is less than or equal to 1.5. The first trailing edge has a main angle that is included between 10° and 30°, and the axis of rotation is situated at a first distance from the first leading edge, that is included between 15% and 35% of the chord.

1 . A rotary flap liable to turn about a longitudinal axis of rotation ( 4 ) defined according to the first span ( 5 ) of said flap ( 1 ), said flap ( 1 ) having a profile ( 6 ) extending along the chord (CO) and comprising a first leading edge ( 7 ), a first trailing edge ( 8 ), an inner surface ( 9 ) and an outer surface ( 10 ), characterized in that: 
 said inner surface ( 9 ) and said outer surface ( 10 ) have, beyond 25% of the flap chord CO, shapes that are not concave;    said first trailing edge ( 8 ) has a main angle (α) included between 10° and 30°; and    said axis of rotation ( 4 ) is situated at a first distance (C1) from said first leading edge ( 7 ), which is included between 15% and 35% of the chord (CO) of said flap ( 1 ).    
   
   
       2 . A flap according to the  claim 1 , characterized in that said first leading edge ( 7 ) has a rounded shape provided with a more or less constant curve radius (R)  
   
   
       3 . A flap according to the  claim 1 , characterized in that said first leading edge ( 7 ) has an elliptical shape whose first major axis to minor axis quotient is less than or equal to 1.5.  
   
   
       4 . A flap according to  claim 1 , 
 characterized in that said inner surface ( 9 ) has a more or less linear shape.    
   
   
       5 . A flap according to  claim 1 , 
 characterized in that said inner surface ( 9 ) has a more or less convex shape.    
   
   
       6 . A flap according to  claim 1 , 
 characterized in that said outer surface ( 10 ) has a more or less linear shape.    
   
   
       7 . A flap according to  claim 1 , 
 characterized in that said outer surface ( 10 ) has a more or less convex shape.    
   
   
       8 . A flap according to  claim 1 , 
 characterised in that said main angle (α) is approximately 20°.    
   
   
       9 . A flap according to  claim 1 , 
 characterized in that said first trailing edge ( 8 ) has an elliptical shape whose second major axis to minor axis quotient is greater than or equal to 1.5.    
   
   
       10 . A flap according to the  claim 9 , characterized in that said second major axis to minor axis quotient is approximately equal to 2.  
   
   
       11 . A flap according to  claim 1 , 
 characterized in that said axis of rotation ( 4 ) of flap ( 1 ) is situated at a first distance (C1) from said first leading edge ( 7 ) corresponding more or less to 25.5% of the chord (CO).