Airflow control devices based on active materials
View Patent ↗An airflow control device comprises a body and an active material in operative communication with the body. The active material, such as shape memory material, is operative to change at least one attribute in response to an activation signal. The active material can change its shape, dimensions and/or stiffness producing a change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness to control vehicle airflow to better suit changes in driving conditions such as weather, ground clearance and speed, while reducing maintenance and the level of failure modes. As such, the device reduces vehicle damage due to inadequate ground clearance, while increasing vehicle stability and fuel economy. An activation device, controller and sensors may be employed to further control the change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness of the device. A method for controlling vehicle airflow selectively introduces an activation signal to initiate a change of at least one feature of the device that can be reversed upon discontinuation of the activation signal.
1. An air deflector for a vehicle, comprising:
a diverter fixedly attached to the mandrel and positioned in an airflow, wherein the mandrel is rotatably mounted to a stationary surface; and
an active material in operative communication with the mandrel, the active material being operative to change at least one attribute in response to an activation signal, wherein an airflow across the diverter changes with the change in the at least one attribute of the active material.
2. The air deflector of claim 1 , wherein the active material comprises a shape memory alloy, a shape memory polymer, an electroactive polymer, a mnagnetorheological elastomer, a piezoelectric material or combinations comprising at least one of the foregoing materials.
3. The air deflector of claim 1 , wherein the active material comprises a wire formed of a shape memory alloy, wherein one end of the wire is fixedly attached to a stationary surface and the other end of the wire is fixedly attached to the mandrel at a location effective to cause rotation of the mandrel upon activation of the shape memory alloy.
4. The air deflector of claim 1 , wherein the active material comprises a torsional spring formed of a shape memory alloy and disposed within an end of the mandrel, wherein one end of the torsional spring is fixedly attached to a stationary surface and the other end of the wire is fixedly attached to the mandrel at a location effective to cause rotation of the mandrel upon activation of the shape memory alloy.
5. The air deflector of claim 1 , wherein the active material comprises a spring formed of a shape memory alloy, wherein one end of the spring is fixedly attached to a stationary surface and the other end of the wire is fixedly attached to the mandrel or the diverter at a location effective change a position of the diverter upon activation of the shape memory alloy.
6. The air deflector of claim 1 , wherein the activation signal comprises a thermal activation signal, a magnetic activation signal, an electrical activation signal, chemical activation signal or a combination comprising at least one of the foregoing signals.
7. The air deflector of claim 1 , further comprising an activation device adapted to provide an activation signal to the air deflector.
8. The air deflector of claim 1 further comprising at least one sensor and a controller in operative communication with the active material.
9. The air deflector of claim 1 , wherein the air deflector comprises a vehicle air dam; a fender flare; a side skirt crib; a cab; rear and tailgate spoilers; louvers for controlling airflow through radiator, other heat exchangers, the engine compartment, over the drive train and transmission; and air and wind deflectors for roof top, sunroof and vent windows.
10. The air deflector of claim 1 , wherein the activation signal is triggered by a predetermined speed of the vehicle, wherein the active material changes at least one attribute when a speed of the vehicle exceeds the predetermined speed, and wherein the active material returns to an original state of the at least one attribute when the speed of the vehicle is below the predetermined speed.
11. The air deflector of claim 1 , wherein the vehicle comprises an automobile, an over the highway tractor, a boat, a motorcycle, an airplane, or a bobsled.
12. The air deflector of claim 1 , wherein the active material comprises a torque tube formed of a shape memory alloy that is pre-twisted in the cold state, wherein the torque tube is in operative communication with the diverter and the mandrel to effect rotation of the diverter upon activation of the shape memory alloy.
13. The air deflector of claim 12 , wherein the torque tube is in fluid communication with a fluid.
14. The air deflector of claim 13 , wherein the fluid is an automotive coolant.