Pneumatic aerodynamic control and drag-reduction system for ground vehicles

• US 5,908,217 A
• Filed: 07/17/1995
• Issued: 06/01/1999
• Est. Priority Date: 07/17/1995
• Status: Expired due to Term

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Englar, Robert J.
• Primary Examiner(s): Pedder, Dennis H.
• Application Number:
  US08/503,185
• Time in Patent Office: 1,415 Days
• Field of Search: 296/180.4, 296/180.1, 296/208, 296/180.5, 296/185
• US Class Current: 296/180.1
• CPC Class Codes: B62D 35/00 Vehicle bodies characterised by streamlining
• CPC Class Codes: B62D 37/02 by aerodynamic means

Abstract

A blowing system for controlling the aerodynamics of a ground vehicle comprises a source of compressed air, a valve for regulating the flow of the compressed air, and a plenum for discharging the air at a rear portion of the vehicle. The air discharged through the plenum prevents flow separation and consequently reduces the drag on the vehicle. It may also increase lift, reducing effective weight and thus rolling resistance of the tires, or decrease lift to improve tire traction and handling. The blowing system may have separate plenums for the left and right sides of the vehicle whereby vortex roll-up and flow separation which occur on only one side of the vehicle may be eliminated. Asymmetrical blowing of only one plenum will produce rolling and yawing moments to restore the vehicle'"'"'s lateral/directional stability when exposed to a side wind. Further, the blowing system may have a lower plenum for reattaching flow, generating a negative lift or download to increase traction, braking, and handling and for generating pitch trim. The blowing system may have a number of sensors for detecting various conditions, such as the direction and pressure of a relative wind, turbulence at the rear of the vehicle, braking, or angle of steering. The blowing system may be responsive to one or more of these conditions to selectively adjust the aerodynamics of the vehicle.

Claims

1. An airflow control system for use with a ground vehicle for adjusting aerodynamic forces acting on said vehicle, said system comprising:

a around vehicle having a body said vehicle body having an outer surface comprising an upper outer surface and a lower outer surface;

a source of air under pressure said source of air internal to the body of said ground vehicle;

a first valve for receiving said air from said source and for regulating a first flow of said air;

means for receiving said first flow of air from said first valve and for discharging said air through a first opening in the upper outer surface of said ground vehicle, said air being discharged tangentially to the upper outer surface;

a second valve for receiving said air from said source and for regulating a second flow of said air;

a second means for receiving said second flow of air from said second valve and for discharging said air through a second opening in the lower outer surface of said ground vehicle, said air being discharged tangentially to the lower outer surface; and

means for controlling said first valve and said second valve, said controlling means independently adjusting said flow of air through each valve;

wherein said air discharged through said first opening and said second opening augments aerodynamic forces acting on said ground vehicle and reduces flow separation downstream of said openings.

2. The airflow control system of claim 1, wherein said controlling means adjusts said air flowing through said first and second valves so that said air discharged through said openings generates a positive lift on said ground vehicle for reducing tire rolling friction.

3. The airflow control system of claim 1, wherein said controlling means adjusts said air flowing through said first and second valves so that said air discharged through said openings generates a negative lift force on said ground vehicle for increasing a download on said ground vehicle for augmenting braking and handling characteristics of said ground vehicle.

4. The airflow control system of claim 1, wherein said controlling means adjusts said air flows through said valves so that said air discharged through said openings generates a nose-down pitch on said ground vehicle.

5. The airflow control system of claim 1, wherein said controlling means adjusts said air flows through said valves so that said air discharged through said openings generates a nose-up pitch on said ground vehicle.

6. The airflow control system of claim 1, wherein said controlling means adjusts said air flowing through said valves so that said air discharged through said openings counteracts vortex roll-up on said ground vehicle.

7. The airflow control system of claim 1, further comprising at least one sensor for detecting turbulence and wherein said controlling means adjusts said flow through said first and second valves based on an output from said sensor.

8. The airflow control system of claim 1, further comprising means for detecting a direction and pressure of a relative wind and wherein said controlling means adjusts said flow through said first and second valves based upon said direction and pressure.

9. The airflow control system of claim 8, wherein said detecting means comprises a plurality of sensors located about said ground vehicle for detecting a differential amount of pressure between a pressure on said surface of said ground vehicle and a reference pressure.

10. A method for controlling aerodynamic forces acting on a ground vehicle by blowing air, said method comprising the steps of:

routing compressed air from a source to a first valve and a second valve;

adjusting a flow of said compressed air with said valves;

receiving said flow of compressed air from said first valve in a first plenum, and receiving said flow of compressed air from said second valve in a second plenum;

discharging said flow of compressed air out of said first plenum through a first opening in an upper surface of said ground vehicle and discharging said flow of compressed air out of said second plenum through a second opening in a lower surface of said ground vehicle, wherein said flow of compressed air is discharged tangential to said outer surface of said ground vehicle;

controlling said first valve and said second valve independently to adjust the air flow out of said first opening and said second opening; and

generating a negative lift force on said ground vehicle.

11. The method of claim 10, wherein said step of controlling comprises the steps of:

detecting a change in aerodynamic forces acting on said ground vehicle; and

controlling said air flow out of said first and second openings to compensate for said change in aerodynamic forces acting on said ground vehicle.

12. The method of claim 11, wherein said step of detecting a change in aerodynamic forces acting on said ground vehicle comprises detecting a direction and a pressure of a relative wind.

13. The method of claim 11, wherein said step of detecting a change in aerodynamic forces acting on said ground vehicle comprises detecting turbulence at a rear portion of said ground vehicle.

14. The method of claim 10, wherein said step of controlling comprises the steps of:

detecting a change in acceleration of said ground vehicle; and

controlling said air flow out of said first and second openings to adjust a lift force and a downforce acting on said ground vehicle.

15. The method of claim 10, wherein said step of generating a negative lift force comprises discharging a greater mass of compressed air out of said second opening than out of said first opening.

16. An airflow control system for use with a ground vehicle for adjusting aerodynamic forces acting on said ground vehicle, said system comprising:

a ground vehicle having a body, said vehicle body having an outer surface comprising an upper outer surface and a lower outer surface, said ground vehicle having a left side and a right side;

a source of air under pressure, said source of air internal to the body of said ground vehicle;

a left valve for receiving and regulating a first flow of air from said source of air under pressure;

a first means for receiving said first flow of air from said left valve and for discharging said air through a first opening in the outer surface of said ground vehicle, said first opening on the left side of said ground vehicle, said air being discharged tangentially to the ground vehicle outer surface;

a right valve for receiving and regulating a second flow of air from said source of air under pressure;

a second means for receiving said second flow of air from said right valve and for discharging said air through a second opening in the outer surface of said ground vehicle, said second opening on the right side of said ground vehicle, said air being discharged tangentially to the ground vehicle outer surface; and

means for independently controlling said left valve and said right valve, said controlling means independently adjusting said flow of air through each valve such that the flow of air out of said first and second openings are modified independently;

wherein said air discharged through said first opening and said second opening augments aerodynamic forces acting on said vehicle and reduces flow separation downstream of said openings.

17. The airflow control system of claim 16, wherein said controlling means adjusts said air flows through said first and second valves so that said air discharged through said openings generates a positive lift on said vehicle for reducing tire rolling friction on a ground based vehicle.

18. The airflow control system of claim 16, wherein said controlling means adjusts said air flows through said first and second valves so that said air discharged through said openings generates a negative lift force on said vehicle for increasing a download on said vehicle for augmenting braking and handling characteristics of said vehicle.

19. The airflow control system of claim 16, wherein said controlling means adjusts said air flows through said valves so that said air discharged through said openings generates a nose-down pitch.

20. The airflow control system of claim 16, wherein said controlling means adjusts said air flows through said valves so that said air discharged through said openings generates a nose-up pitch.

21. The airflow control system of claim 16, wherein said controlling means adjusts said air flows through said valves so that said air discharged through said openings counteracts vortex roll-up.

22. The airflow control system of claim 16, further comprising at least one sensor for detecting turbulence and wherein said controlling means adjusts said flow through said left and right valves based on an output from said sensor.

23. The airflow control system of claim 16, further comprising means for detecting a direction and pressure of a relative wind and wherein said controlling means adjusts said flow through said left and right valves independently based upon said direction and pressure.

24. The airflow control system of claim 23, wherein said detecting means comprises a plurality of sensors located about said vehicle for detecting a differential amount of pressure between a pressure on said surface of said vehicle and a reference pressure.

25. A method for adjusting aerodynamic forces acting on a ground vehicle by blowing air, said method comprising the steps of:

providing a ground vehicle having a body with an outer surface;

routing compressed air from a source of air under pressure to a valve, said source of air under pressure internal to said ground vehicle;

adjusting a flow of said compressed air with said valve;

receiving a first flow of compressed air from said valve in a left plenum positioned on a left side of said ground vehicle, and receiving a second flow of compressed air from said valve in a right plenum on a right side of said ground vehicle;

discharging said first flow of compressed air from said left plenum and through a first opening in a left side of said outer surface of said ground vehicle;

discharging said second flow of compressed air from said right plenum and through a second opening in a right side of said outer surface of said ground vehicle;

directing said first and second flows of compressed air out of said first and second openings to discharge tangential to said outer surface of said ground vehicle;

generating a region of increased negative pressure along the outer surface of the ground vehicle downstream of said first and second openings, said negative pressure region altering the aerodynamic forces acting on said ground vehicle and creating rolling and yawing moments on said ground vehicle;

detecting a relative wind acting on said ground vehicle; and

controlling said valve to adjust said first and second flows of compressed air out of said first and second openings to compensate for said relative wind.

26. The method of claim 25, wherein said detecting step comprises detecting a direction and pressure of a relative wind with pressure probes on said outer surface of said ground vehicle.

27. A method for controlling aerodynamic forces acting on a ground vehicle by blowing air, said method comprising the steps of:

routing compressed air from a source of pressurized air through a first control valve and a second control valve;

receiving a first flow of compressed air from said first control valve in a first plenum, and receiving a second flow of compressed air from said second control valve in a second plenum;

discharging said first flow of compressed air out of said first plenum through a first opening in a left side of an outer surface of said ground vehicle, said first flow discharging tangential to said outer surface;

discharging said second flow of compressed air out of said second plenum through a second opening in a right side of an outer surface of said ground vehicle, said second flow discharging tangential to said outer surface; and

reducing vortex roll up on said ground vehicle.

28. The method of claim 27, wherein said step of reducing vortex roll up comprises:

detecting a relative wind acting on said vehicle;

adjusting said first and second control valves in response to said relative wind; and

creating differential flow rates of air out of said first and second openings in order to compensate for said relative wind.