Tailpipe collar

Abstract

An exhaust system for a vehicle may include a tailpipe and a collar. The tailpipe may be adapted to receive exhaust gas from an internal combustion engine and may include an outlet. The collar may include an inner surface, an outer surface, an air-inlet, and an air-outlet. The inner surface may be radially spaced apart from the tailpipe and may at least partially surround the outlet of the tailpipe. The inner and outer surfaces may be shaped to form a profile that causes a first air-flow to accelerate upon flowing between the inner surface and the tailpipe to a first velocity that is faster than a second velocity of a second air-flow. The second air-flow may be flowing adjacent the outer surface and radially outward relative to the outer surface.

What is claimed is: 
     
         1 . An exhaust system for a vehicle comprising:
 a tailpipe adapted to receive exhaust gas from an internal combustion engine and including an outlet; and   a collar including an inner surface, an outer surface, an air-inlet, and an air-outlet, the inner surface being radially spaced apart from the tailpipe and at least partially surrounding the outlet of the tailpipe, the inner and outer surfaces being shaped to form a profile that causes a first air-flow to accelerate upon flowing between the inner surface and the tailpipe to a first velocity that is faster than a second velocity of a second air-flow flowing adjacent the outer surface and radially outward relative to the outer surface.   
     
     
         2 . The exhaust system of  claim 1 , wherein a first pressure of fluid between the air-inlet and the air-outlet is lower than a second pressure of fluid upstream of the outlet of the tailpipe. 
     
     
         3 . The exhaust system of  claim 1 , wherein the inner and outer surfaces form an annular portion that extends angularly around the entire outlet of the tailpipe. 
     
     
         4 . The exhaust system of  claim 1 , wherein the inner and outer surfaces extend angularly around only a portion of the outlet of the tailpipe. 
     
     
         5 . The exhaust system of  claim 1 , wherein the inner surface of the collar curves radially inward. 
     
     
         6 . The exhaust system of  claim 1 , wherein the inner and outer surfaces of the collar cooperate to form an airfoil. 
     
     
         7 . The exhaust system of  claim 1 , wherein an angle between a chord line of the airfoil and a longitudinal axis of the collar is about two degrees. 
     
     
         8 . The exhaust system of  claim 1 , wherein the collar includes at least one support member extending radially between the tailpipe and the inner surface. 
     
     
         9 . The exhaust system of  claim 8 , wherein the collar includes an inner ring attached to the at least one support member and engaging the tailpipe. 
     
     
         10 . The exhaust system of  claim 1 , wherein the outlet of the tailpipe includes a nozzle portion. 
     
     
         11 . A tailpipe collar comprising:
 an outer ring configured to least partially surround a tailpipe of a vehicle, the outer ring including an inner surface and an outer surface that cooperate to form an airfoil-shaped cross section; and   a spoke connected to the outer ring and extending radially inward therefrom, the spoke adapted to support the outer ring relative to the tailpipe.   
     
     
         12 . The tailpipe collar of  claim 11 , further comprising an inner ring adapted to engage and at least partially surround the tailpipe, the outer ring being disposed radially outward relative to the inner ring, the spoke extending between and attached to the inner and outer rings. 
     
     
         13 . The tailpipe collar of  claim 11 , wherein an outlet of the tailpipe is disposed between an air-inlet and an air-outlet defined by the outer ring and the outer ring receives exhaust gas from the outlet of the tailpipe. 
     
     
         14 . The tailpipe collar of  claim 13 , wherein the outer ring receives air through the air-inlet when the vehicle is moving in a forward direction. 
     
     
         15 . The tailpipe collar of  claim 11 , wherein a first pressure of fluid between the air-inlet and the air-outlet is lower than a second pressure of fluid upstream of the outlet of the tailpipe. 
     
     
         16 . The tailpipe collar of  claim 11 , wherein the outer ring extends angularly around the entire outlet of the tailpipe. 
     
     
         17 . The tailpipe collar of  claim 11 , wherein the outer ring extends angularly around only a portion of the outlet of the tailpipe. 
     
     
         18 . The tailpipe collar of  claim 11 , wherein the inner surface of the outer ring curves radially inward. 
     
     
         19 . The tailpipe collar of  claim 11 , wherein the outer ring is disposed at an angle-of-attack of about two degrees. 
     
     
         20 . The tailpipe collar of  claim 11 , wherein the outer ring is substantially circular.