Device for reducing the form drag of vehicles

• US 5,820,203 A
• Filed: 10/30/1997
• Issued: 10/13/1998
• Est. Priority Date: 04/19/1995
• Status: Expired due to Fees

• Current Assignee: Fiat Auto S.p.A., Politecnico Di Torino Dipartimento Di Energetica
• Original Assignee: Fiat Auto S.p.A., Politecnico Di Torino Dipartimento Di Energetica
• Inventors: Di Giusto, Nevio, Morelli, Alberto
• Primary Examiner(s): PAPE, JOSEPH
• Application Number:
  US08/961,238
• Time in Patent Office: 348 Days
• Field of Search: 296/180.1, 296/198, 296/208, 180/903, 301/6.3, 301/6.91, 188/264 A, 188/71.6, 280/848, 280/850, 280/851
• US Class Current: 296/180.1
• CPC Class Codes: B60C 23/18 Tyre cooling arrangements , e.g. heat shields wheels with cooling fins B60B19/10
• CPC Class Codes: B62D 25/16 Mud-guards or wings; Wheel cover panels equipped with means for freeing wheels or tyres from foreign matter B60S
• CPC Class Codes: B62D 35/00 Vehicle bodies characterised by streamlining
• CPC Class Codes: B62D 35/02 Streamlining the undersurfaces B62D35/005, B62D35/007, B62D35/008 take precedence
• CPC Class Codes: Y02T 10/88 Optimized components or subsystems, e.g. lighting, actively controlled glasses
• CPC Class Codes: Y10S 180/903 Airstream reactive vehicle or vehicle structure

Abstract

The device includes fan devices associated with each wheel of the vehicle for creating respective auxiliary flows. Conveying devices, associated with the wheel housing, direct the auxiliary flows to a distributor provided with an outlet opening, so that the air flows from the distributors sweep along the bottom of the motor vehicle and exit in the area of the truncated tail portion of the vehicle body in order to create, at least partially, a so-called tailstream produced by a stationary ring vortex.

Claims

1. A device for reducing the form drag of a vehicle having an upper surface, side surfaces, a bottom surface and a truncated tail portion, said vehicle having wheel housings and a rotatable wheel mounted in each housing, said device comprising fanning means operatively connected with each wheel of the vehicle for creating auxiliary air flows and conveying means connected to each wheel housing and comprising a distributor provided with an outlet opening in the direction of said truncated tail portion, each conveying means directing an auxiliary air flow from each wheel housing to said outlet opening wherein said outlet openings are substantially laterally offset relative to each other to provide a uniform flow of air along a bottom edge of said truncated tail portion of cooperation with air flows along said upper and side surfaces of the vehicle to facilitate creation of a stationary ring vortex.

2. A device according to claim 1, wherein the fanning means operatively connected with each wheel are constituted by at least one substantially radial blade set causing a reaction effect which imparts to the airflows both axial and centrifugal actions.

3. A device according to claim 2, wherein the wheels have respective hub cap bosses with said fanning means including air intake means having curved blade sets of one piece construction with the hub cap boss of the respective wheel.

4. A device according to claim 1, wherein the conveying means connected to each wheel housing comprise a plurality of ducts which converge in the distributor and wherein the distributor is provided with a flattened horizontal outlet opening capable of creating a substantial entraining effect on a normal air layer sweeping along the bottom surface of the vehicle.

5. A device according to claim 1, wherein the transverse extent of the outlet openings of the distributors effect substantially the air flow of a bottom peripheral portion of the truncated tail portion, the energetic potential of air flow at the bottom peripheral portion being increased in order to render it uniform with air flow along remaining peripheral portions of the truncated tail portion.

6. A device according to claim 4, wherein the wheel housing includes a cavity, the plurality of ducts being delimited in the cavity of the wheel housing by corresponding fixed blades which are capable of directing the auxiliary air flow towards the distributor, under acceleration, of reducing the overall energy losses of the air flow and of eliminating the vortices having dimensions greater than those corresponding to the transverse dimensions of the ducts.

7. A device according to claim 6, wherein the blades have dimensional means for causing the currents of the individual ducts to arrive in the rear distributor at approximately the same speed and pressure.

8. A device according to claim 2, wherein each wheel comprises a brake drum having an auxiliary blade set thereon for increasing the reaction effect of the radial blade set.

9. A device according to claim 1, wherein said fanning means comprises fins on a wheel disc which are capable of increasing the effect of entraining the flow produced as a result of the air coming into contact with the wheel.

10. A device according to claim 1, wherein each wheel housing is equipped with a lower contour having a pointed corner.

11. A device according to claim 1, wherein a portion of the auxiliary airflows is used for cooling the brakes and the wheels.