초록 ▼

A body adapted to move downstream through a fluid has a downstream extending smooth surface terminating at a blunt base. A plurality of adjacent U-shaped, downstream extending troughs in the smooth surface intersect the blunt base to form trough outlets. The troughs are appropriately spaced apart, s

A body adapted to move downstream through a fluid has a downstream extending smooth surface terminating at a blunt base. A plurality of adjacent U-shaped, downstream extending troughs in the smooth surface intersect the blunt base to form trough outlets. The troughs are appropriately spaced apart, sized and configured to flow full over their entire length and cause fluid to flow into the space immediately behind the blunt base, thereby reducing base drag on the body.

대표청구항 ▼

A vehicle adapted to be disposed in a fluid moving downstream relative thereto, said vehicle having a blunt rear end surface and a first surface defining a first plurality of adjacent, downstream extending troughs, each of said troughs terminating at said rear end surface to form a plurality of spac

A vehicle adapted to be disposed in a fluid moving downstream relative thereto, said vehicle having a blunt rear end surface and a first surface defining a first plurality of adjacent, downstream extending troughs, each of said troughs terminating at said rear end surface to form a plurality of spaced apart trough outlets in said end surface, the sum of the downstream projected areas of all of said trough outlets being no greater than about 30% of the downstream projected area of said rear end surface, each of said troughs including a pair of downstream extending sidewall surfaces which intersect said rear end surfaces to form side edges of said trough outlets, wherein a first portion of the area of said rear end surface extends laterally from each of said side edges to the side edge of an adjacent trough outlet over the full length of each of said side edges, wherein each of said troughs has an inlet and gradually increases from no depth at said inlet to its maximum depth, wherein the contour and dimensions of said troughs and the size of said first area portions are such as to ensure that each trough flows full throughout its length and causes fluid to flow into the space immediately downstream of said rear end surface to reduce base drag.