Vehicle Underbody Fairing

• US 20090146453A1
• Filed: 10/22/2008
• Published: 06/11/2009
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: Ortega, Jason M., Salari, Kambiz, McCallen, Rose
• Granted Patent: US 7,828,368 B2
• Time in Patent Office: Days
• US Class Current: 296/180.400
• CPC Class Codes: B62D 35/001 For commercial vehicles or tractor-trailer combinations, e.g. caravans
• CPC Class Codes: B62D 35/02 Streamlining the undersurfaces B62D35/005, B62D35/007, B62D35/008 take precedence
• CPC Class Codes: Y02T 10/82 Elements for improving aerodynamics
• CPC Class Codes: Y02T 10/88 Optimized components or subsystems, e.g. lighting, actively controlled glasses

Abstract

A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

Claims

1. A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly supporting a vehicle body from thereunder, comprising:

a fairing body having a fairing front end, a fairing rear end, and a tapered aerodynamic surface comprising a bottom section flanked by left and right side sections which together extend from the fairing front end to the fairing rear end with a substantially U-shaped cross-section that tapers in both height and width; and

mounting means for securing the fairing body to an underside surface of the vehicle body, so that the fairing front end is adjacent to and downstream of the vehicle wheel assembly and the bottom section of the tapered aerodynamic surface rises towards the underside surface of the vehicle body as it extends downstream from the fairing front end to the fairing rear end,

whereby the mounted fairing body reduces the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly.

2. The vehicle underbody fairing apparatus of claim 1,

wherein the width of the substantially U-shaped cross-section at the front end is substantially equivalent to the width of the vehicle wheel assembly.

3. The vehicle underbody fairing apparatus of claim 2,

wherein the height of the substantially U-shaped cross-section at the front end is substantially equivalent to the height of the vehicle wheel assembly.

4. The vehicle underbody fairing apparatus of claim 1,

wherein the substantially U-shaped cross-section tapers to a vertex at the fairing rear end, and the mounting means secures the fairing body so that the vertex is at substantially the same level as the underside surface of the vehicle body.

5. The vehicle underbody fairing apparatus of claim 1,

wherein the fairing body includes a front panel connected edgewise to the tapered aerodynamic surface at the fairing front end.

6. The vehicle underbody fairing apparatus of claim 1,

wherein the bottom section of the tapered aerodynamic surface has a recessed channel for channeling airflow coming from under an axle of the vehicle wheel assembly.

7. The vehicle underbody fairing apparatus of claim 1,

wherein the tapered aerodynamic surface is contoured so as to be without sharp edges.

8. The vehicle underbody fairing apparatus of claim 1,

wherein at least one of the height and width of the substantially U-shaped cross-section tapers at a non-uniform rate so that the bottom section and/or the left and right side sections are curved.

9. The vehicle underbody fairing apparatus of claim 1,

wherein the tapered aerodynamic surface has a plurality of perforations.

10. A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly supporting a vehicle body from thereunder, comprising:

a fairing body having a fairing front end, a fairing rear end, and a tapered aerodynamic surface comprising a bottom section flanked by left and right side sections which together extend from the fairing front end to the fairing rear end with a substantially U-shaped cross-section that tapers in both height and width from a fairing front end height and width that are substantially equivalent to the height and width respectively of the vehicle wheel assembly to a vertex at the fairing rear end; and

mounting means for securing the fairing body to an underside surface of the vehicle body, so that the fairing front end is adjacent to and downstream of the vehicle wheel assembly, the bottom section of the tapered aerodynamic surface rises towards the underside surface of the vehicle body as it extends downstream from the fairing front end to the fairing rear end, and the vertex is at substantially the same level as the underside surface of the vehicle body,

whereby the mounted fairing body reduces the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly.

11. The vehicle underbody fairing apparatus of claim 10,

wherein the fairing body includes a front panel connected edgewise to the tapered aerodynamic surface at the fairing front end.

12. The vehicle underbody fairing apparatus of claim 10,

wherein the bottom section of the tapered aerodynamic surface has a recessed channel for channeling airflow coming from under an axle of the vehicle wheel assembly.

13. The vehicle underbody fairing apparatus of claim 10,

wherein the tapered aerodynamic surface is contoured so as to be without sharp edges.

14. The vehicle underbody fairing apparatus of claim 10,

wherein at least one of the height and width of the substantially U-shaped cross-section tapers at a non-uniform rate so that the bottom section and/or the left and right side sections are curved.

15. The vehicle underbody fairing apparatus of claim 10,

wherein the tapered aerodynamic surface has a plurality of perforations.

16. An aerodynamic semi-trailer for use in tractor-trailer towing arrangements, comprising:

a trailer body with a trailer front end and a trailer rear end;

a rear wheel assembly supporting the trailer rear end from thereunder;

a hitch located under the trailer front end for connecting the trailer body to a tractor so that a drive wheel assembly of the tractor supports the trailer front end from thereunder; and

a fairing body located under the trailer body between the front and rear wheel assemblies, said fairing body having a fairing front end adjacent to and downstream of the drive wheel assembly of the tractor when the trailer body is hitched thereto, a fairing rear end downstream of the fairing front end, and a tapered aerodynamic surface comprising a bottom section flanked by left and right side sections which together extend downstream from the fairing front end to the fairing rear end with a substantially U-shaped cross-section that tapers in both height and width, said bottom section rising towards the underside surface of the vehicle body as it extends downstream from the fairing front end to the fairing rear end,

whereby the mounted fairing body reduces the aerodynamic drag caused by the vehicle wheel assembly by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly.

17. The aerodynamic semi-trailer of claim 16,

wherein the width of the substantially U-shaped cross-section at the front end is substantially equivalent to the width of the vehicle wheel assembly.

18. The aerodynamic semi-trailer of claim 17,

wherein the height of the substantially U-shaped cross-section at the front end is substantially equivalent to the height of the vehicle wheel assembly.

19. The aerodynamic semi-trailer of claim 16,

wherein the substantially U-shaped cross-section tapers to a vertex at the fairing rear end, and the mounting means secures the fairing body so that the vertex is at substantially the same level as the underside surface of the vehicle body.

20. The aerodynamic semi-trailer of claim 16,

wherein the fairing body includes a front panel connected edgewise to the tapered aerodynamic surface at the fairing front end.

21. The aerodynamic semi-trailer of claim 16,

wherein the bottom section of the tapered aerodynamic surface has a recessed channel for channeling airflow coming from under an axle of the vehicle wheel assembly.

22. The aerodynamic semi-trailer of claim 16,

wherein the tapered aerodynamic surface is contoured so as to be without sharp edges.

23. The aerodynamic semi-trailer of claim 16,

wherein at least one of the height and width of the substantially U-shaped cross-section tapers at a non-uniform rate so that the bottom section and/or the left and right side sections are curved.

24. The aerodynamic semi-trailer of claim 16,

wherein the tapered aerodynamic surface has a plurality of perforations.