Body provided with a superficial area adapted to reduce drag

1. A body provided with a superficial area adapted to reduce drag when the body is moving relative to a gaseous or watery medium, comprising depressions in said superficial area, wherein the depressions have a greater length than width and are provided in the superficial area so as to collectively shape a curvature provided in a length direction of said depressions in the superficial area, and/or said depressions themselves are provided with a curvature in their length direction, characterized in that the depressions are deprived of sharp edges in a transitional area wherein the depressions meet the superficial area, and that the depressions have a maximum depth (D) relative to the superficial area of 5% of the depressions' width so as to cause that in use a turbulent boundary layer of the gaseous or watery medium adjacent to the superficial area is exposed to lateral excitation with reference to a movement direction of the body relative to the gaseous or watery medium or with reference to a flow direction of said turbulent boundary layer along said superficial area of the body.

2. The body according to claim 1 , characterized in that in the transitional area a radius r exists and that the depressions have a radius R, and that the radius r and the radius R are selected at values to satisfy the relation r>0,1*R.

3. The body according to claim 1 , characterized in that there are multiple curvatures that are provided staggered, parallel or antiparallel with respect to each other in the superficial area.

4. The body according to claim 1 , characterized in that the curvature or curvatures are wavy and comprising a shape of a sinus or cosines or suitable combinations thereof.

5. A method to reduce drag of a body moving relative to a gaseous or watery medium by providing the body with depressions in a superficial area of the body, comprising the step of providing the depressions with a greater length than width in the superficial area of the body so as to collectively shape a curvature in a length direction of said depressions in the superficial area, and/or providing that said depressions themselves have a curvature in their length direction, characterized by providing that the depressions are deprived of sharp edges in a transitional area wherein the depressions meet the superficial area, and providing that the depressions have a maximum depth (D) relative to the superficial area of 5% of the smallest of the depressions' width so as to cause that a turbulent boundary layer of the gaseous or watery medium adjacent to the superficial area of the body is exposed to lateral excitation with reference to a movement direction of the body relative to the gaseous or watery medium or with reference to a flow direction of said turbulent boundary layer along said superficial area of the body.

6. The method according to claim 5 , characterized by providing that in the transitional area a radius r exists and that the depressions have a radius R, and that the radius r and the radius R are selected at values to satisfy the relation r>0,1*R.

7. The method according to claim 5 , characterized by providing the superficial area with multiple curvatures in a staggered, parallel or antiparallel orientation with respect to each other.

8. The method according to claim 5 , characterized by providing the curvature or curvatures with the shape of a sinus or cosines, or suitable combinations thereof.

9. Body according to claim 1 , wherein, during use, vortices are prevented to form in the depressions.

10. Method according to claim 5 , wherein, during use, vortices are prevented to form in the depressions.