Drag reducing mirror assemblies for vehicles
A side-view mirror assembly for a vehicle is disclosed. The mirror assembly may generally include a mirror housing configured to support a mirror. The mirror housing may define an airfoil shape have a first side surface and a second side surface extending between a forward edge and an aft edge. In addition, the mirror housing may be movable between a first position, wherein the mirror housing is aerodynamically aligned with an airflow flowing past the vehicle, and a second position, wherein the mirror reflects a rearwardly extending side-view of the vehicle.
1. A method for enhancing the operation of a vehicle having a vision system configured to provide a rearwardly extending side-view of the vehicle, the method comprising:
operating the vehicle with a side-view mirror assembly installed thereon, the mirror assembly including a mirror housing defining an airfoil shape have a first side surface and a second side surface extending between a forward edge and an aft edge;
positioning the mirror housing at a first position at which the mirror housing is aerodynamically aligned with an airflow flowing past the vehicle when the vision system is being used to provide the rearwardly extending side-view of the vehicle, wherein a mirror of the mirror assembly only reflects a view directed towards a portion of the vehicle when the mirror housing is located at the first position; and
moving the mirror housing to a second position at which the mirror housing is not aerodynamically aligned with the airflow flowing past the vehicle when the vision system is not being used to provide the rearwardly extending side-view of the vehicle, Wherein the mirror reflects the rearwardly extending side-view of the vehicle when the mirror is moved to the second position.
2. The method of claim 1 , further comprising moving the mirror housing back to the first position when the vision system is again being used to provide the rearwardly extending side-view of the vehicle.
3. The method of claim 1 , wherein, when in the first position, the mirror housing is oriented relative to the airflow such that a net thrusting force is generated in a direction of travel of the vehicle.
4. The method of claim 1 , wherein, when in the second position, the mirror housing is oriented relative to the airflow such that a net drag force is generated in a direction opposite a direction of travel of the vehicle.
5. The method of claim 1 , wherein the forward edge of the mirror housing defines a leading edge of the airfoil shape and the aft edge defines a trailing edge of the airfoil shape.
6. The method of claim 5 , wherein the trailing edge is configured as a sharp trailing edge.
7. The method of claim 1 , wherein the mirror housing defines a width between the first side surface and the second side surface and further defines a length between the forward edge and the aft edge, the length being at least three times greater than the width.
8. The method of claim 1 , wherein the airflow is oriented at an airflow angle relative to a direction of travel of the vehicle ranging from about 15 degree to about 25 degrees.
9. The method of claim 8 , wherein a chord line is defined between the forward edge and the aft edge, wherein positioning the mirror housing at the first position comprises positioning the mirror housing such that the chord line is oriented at an angle relative to the direction of travel of the vehicle that is equal to the airflow angle minus a reference angle, the reference angle corresponding to an angle-of-attack of the mirror housing.
10. The method of claim 9 , wherein the reference angle ranges from about −5 degrees to about 25 degrees.
11. A vehicle having a vision system configured to provide a rearwardly extending side-view of the vehicle, the vehicle further comprising:
a chassis;
a cab supported by the chassis;
mounting structure coupled to and extending outwardly from the cab; and
a mirror assembly coupled to the mounting structure, the mirror assembly comprising:
a mirror housing configured to support a mirror, the mirror housing defining an airfoil shape have a first side surface and a second side surface extending between a forward edge and an aft edge, the mirror housing being configured to be moved to a first position when the vision system is being used to provide the rearwardly extending side-view of the vehicle and to a second position when the vision system is not being used to provide the rearwardly extending side-view of the vehicle,
wherein, when in the first position, the mirror housing is aerodynamically aligned with an airflow flowing past the vehicle and the mirror only reflects a view directed towards a portion of the vehicle, and wherein, when in the second position, the mirror housing is not aerodynamically aligned with the airflow flowing past the vehicle and the mirror reflects the rearwardly extending side-view of the vehicle.
12. The vehicle of claim 11 , wherein, when in the first position, the mirror housing is oriented relative to the airflow such that a net thrusting force is generated in a direction of travel of the vehicle.
13. The vehicle of claim 11 , wherein, when in the second position, the mirror housing is oriented relative to the airflow such that a net drag force is generated in a direction opposite a direction of travel of the vehicle.
14. The vehicle of claim 11 , wherein the forward edge of the mirror housing defines a leading edge of the airfoil shape and the aft edge defines a trailing edge of the airfoil shape.
15. The vehicle of claim 14 , wherein the trailing edge is configured as a sharp trailing edge.
16. The vehicle of claim 11 , wherein the mirror housing defines a width between the first side surface and the second side surface and further defines a length between the forward edge and the aft edge, the length being at least three times greater than the width.
17. The vehicle of claim 11 , wherein the airflow is oriented at an airflow angle relative to a direction of travel of the vehicle ranging from about 15 degree to about 25 degrees.
18. The vehicle of claim 17 , wherein a chord line is defined between the forward edge and the aft edge, the chord line being oriented at an angle relative to the direction of travel of the vehicle that is equal to the airflow angle minus a reference angle when the mirror housing is located at the first position, the reference angle corresponding to an angle-of-attack of the mirror housing.
19. The vehicle of claim 18 , wherein the reference angle ranges from about −5 degrees to about 25 degrees.