Aerodynamically Enhanced Appendage Coverings

Abstract

An aerodynamically enhanced appendage covering includes a first portion that is not subject to significant airflow and a second portion that is positioned to engage significantly more airflow when placed on a moving body. At least a part of the second portion includes an aerodynamically enhanced area. The aerodynamically enhanced area including a first frontal zone, a second turbulence inducing zone, and a third rear zone. The frontal zone is configured to have a relatively smooth surface for inducing a relatively lesser amount of turbulence on air flowing past than the second zone. The second zone has a relatively less smooth surface and includes a plurality of turbulence-inducing features configured for creating a boundary layer for inducing turbulence in air flowing past the second zone.

What is claimed is: 
     
         1 . An aerodynamically enhanced appendage covering comprising a first portion that is not subject to significant airflow and a second portion that is positioned to engage significantly more airflow when placed on a moving body, at least a part of the second portion including an aerodynamically enhanced area,
 the aerodynamically enhanced area including a first frontal zone, a second turbulence inducing zone, and a third rear zone, the frontal zone being configured to have a relatively smooth surface for inducing a relatively lesser amount of turbulence on air flowing past than the second zone, the second zone having a relatively less smooth surface and including a plurality of turbulence-inducing features configured for creating a boundary layer for inducing turbulence in air flowing past the second zone.   
     
     
         2 . The appendage covering of  claim 1  wherein the second zone includes a relatively recessed surface portion and a relatively raised surface portion, wherein the turbulence inducing features are disposed on one of the relatively raised and recessed surface portions. 
     
     
         3 . The appendage covering of  claim 2  wherein the turbulence inducing features are disposed on the relatively recessed surface portion. 
     
     
         4 . The appendage covering of  claim 3  wherein the relatively recessed surface portion comprises a series of spaced, discreet turbulence inducing features. 
     
     
         5 . The appendage covering of  claim 2  wherein the air turbulence inducing features are disposed on the relatively raised surface portion. 
     
     
         6 . The appendage covering of  claim 5  wherein the relatively raised surface portion comprises a series of discrete spaced turbulence inducing features. 
     
     
         7 . The appendage covering of  claim 5  wherein the turbulence inducing features comprise a plurality of discrete turbulence inducing features. 
     
     
         8 . The appendage covering of  claim 7  wherein the turbulence inducing features comprise at least two columns and two rows of discrete turbulence inducing features. 
     
     
         9 . The appendage covering of  claim 7  wherein the turbulence inducing features have a generally delta-like shape with a narrow leading end and a relatively wider trailing end. 
     
     
         10 . The appendage covering of  claim 7  wherein the third zone of the aerodynamically enhanced area includes a relatively smoother surface than the surface of the second zone. 
     
     
         11 . The appendage covering of  claim 10  wherein the second, turbulence inducing zone is disposed between the first and third zones and wherein the third zone includes a third zone raised portion configured and positioned for directing a pair of airs streams flowing past the second zone to merge at the rear of the appendage covering. 
     
     
         12 . The appendage covering of  claim 1  wherein the appendage covering, when placed on a body, has an upwind side and a downwind side, the first zone is disposed at the upwind side of the appendage covering, and the third zone is disposed at the downwind side, and the second zone is disposed between the first and third zones. 
     
     
         13 . The appendage covering of  claim 12  wherein the appendage covering includes an imaginary plane extending laterally to the direction of airflow, and generally bisecting the appendage covering, wherein the turbulence inducing features are disposed on the second zone between about 45 degrees upwind of the plane and 45 degrees downwind of the plane. 
     
     
         14 . The appendage covering of  claim 13  wherein the turbulence inducing features are disposed between about 25 degrees upwind of the plane and 25 degrees downwind of the plane. 
     
     
         15 . The appendage covering of  claim 1  wherein the third zone of the aerodynamically enhanced area includes a relative smoother surface than the surface of the second zone. 
     
     
         16 . The appendage covering of  claim 15  wherein the second, turbulence inducing zone is disposed between the cast and third zones and wherein the third zone includes a third zone raised portion configured and positioned for directing a pair of air streams flowing past the second zone to merge at the rear of the appendage covering. 
     
     
         17 . The appendage covering of  claim 16  wherein the third zone raised portion is ribbon shaped and extends in a direction generally perpendicular to the direction of flow of the air streams. 
     
     
         18 . The appendage covering of  claim 1  wherein the first portion and second portion meet at a transition area that contains no seam. 
     
     
         19 . The appendage covering of  claim 1  wherein the turbulence inducing features add between about 0.9 and 1.5 mm to the thickness of the second zone. 
     
     
         20 . The appendage covering of  claim 1  wherein the turbulence inducing features add between about 1.0 and 1.25 mm to the thickness of the second zone.