Lifting surface provided with at least one rotary flap

Abstract

A lifting surface with a rotary flap 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°. 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 lifting surface ( 3 ) comprising a second leading edge ( 16 ), a second trailing edge ( 2 ), and at least one rotating flap ( 1 ) 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 also a profile ( 6 ) extending along a chord (CO) and comprising a first leading edge ( 7 ), a first trailing edge ( 8 ), and inner surface ( 9 ) and an outer surface ( 10 ), said flap ( 1 ) being arranged to rotate at said second trailing edge ( 2 ) while leaving a clearance ( 13 ) between said second trailing edge ( 2 ) and said first leading edge ( 7 ) of flap ( 1 ), characterized in that: 
 —said inner surface ( 9 ) and said outer surface ( 10 ) have, beyond 25% of the flap ( 1 ) 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 (C 1 ) from said first leading edge ( 7 ), which is included between 15% and 35% of the chord (CO) of said flap ( 1 ).    
   
   
       2 . A lifting surface 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 lifting surface 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 lifting surface according to  claim 1 , characterized in that said inner surface ( 9 ) has a more or less linear shape.  
   
   
       5 . A lifting surface according to  claim 1 , characterized in that said inner surface ( 9 ) has a more or less convex shape.  
   
   
       6 . A lifting surface according to  claim 1 , characterized in that said outer surface ( 10 ) has a more or less linear shape.  
   
   
       7 . A lifting surface according to  claim 1 , characterized in that said outer surface ( 10 ) has a more or less convex shape.  
   
   
       8 . A lifting surface according to  claim 1 , characterized in that said main angle (α) is approximately 20°.  
   
   
       9 . A lifting surface 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 lifting surface according to the  claim 9 , characterized in that said second major axis to minor axis quotient is approximately equal to 2.  
   
   
       11 . A lifting surface according to  claim 1 , characterized in that said axis of rotation ( 4 ) of said flap ( 1 ) is situated at a first distance (C 1 ) from the said first leading edge ( 7 ) corresponding more or less to 25.5% of the chord (CO).  
   
   
       12 . A lifting surface according to  claim 1 , characterized in that said clearance ( 13 ) is included between 1.5% and 3.5% of said chord (CO) of flap ( 1 ).  
   
   
       13 . A lifting surface according to the  claim 12 , characterized in that said clearance ( 13 ) corresponds to approximately 2% of said chord (CO) of flap ( 1 ).  
   
   
       14 . A lifting surface according to  claim 1 , characterized in that said clearance ( 13 ) is included between 0.4% and 0.8% of a total length (L) separating said second leading edge ( 16 ) from said first trailing edge ( 8 ).  
   
   
       15 . A lifting surface according to the  claim 14 , characterized in that said clearance ( 13 ) corresponds to approximately 0.5% of said total length (L).  
   
   
       16 . A lifting surface according to  claim 1 , characterized in that it includes a partial overlap (P) of said first leading edge ( 7 ) by said second trailing edge ( 2 ).  
   
   
       17 . A lifting surface according to the  claim 16 , characterized in that said partial overlap (P) is less than 10% of said chord (CO) of flap ( 1 ).  
   
   
       18 . A lifting surface according to  claim 1 , characterized in that it includes at least one filling means ( 14 ) to seal off the opening caused by said clearance ( 13 ).  
   
   
       19 . A lifting surface according to the  claim 18 , characterized in that said filling means ( 14 ) is located in a reference surface ( 11 ) of the lifting surface ( 3 ).  
   
   
       20 . A lifting surface according to  claim 1 , characterized in that it includes a multitude of flaps ( 1 ) arranged on the second span of said lifting surface ( 3 ), and in that said first span ( 5 ) of each of said flaps ( 1 ) is less than or equal to 15% of said second span.  
   
   
       21 . A lifting surface according to the  claim 20 , characterized in that said first span ( 5 ) of each of said flaps ( 1 ) is included between 7% and 10% of said second span of said lifting surface ( 3 ).