Active turbulence control technique for drag reduction
June 14, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3612446 Preventing marine fouling Method of and apparatus for controlling the boundary layer flow over the surface of a body Electromechanical film and procedure for manufacturing same Method and apparatus for controlling bound vortices in the vicinity of lifting surfaces Ultrasonic drag reduction and lift increase Elastomer membrane enhanced electrostatic transducer Method and apparatus for influencing a laminar turbulent boundary layer transition on bodies in flow Surface for low drag in turbulent flow Patent #: 5114099 InventorAssigneeApplicationNo. 664395 filed on 06/14/1996US Classes:244/204, By controlling boundary layer244/130Aerodynamic resistance reducingExaminersPrimary: Jordan, Charles T.Assistant: Montgomery, Christopher K. Attorney, Agent or FirmForeign Patent References
International ClassB64C 21//10AbstractA method of disrupting a turbulent region of a boundary layer within a fluid flow passing over a surface to decrease momentum transfer, and thus friction drag, between the turbulent flow and the surface. Bending waves are generated on the surface to impose velocity and/or pressure oscillations within the turbulent region and disrupt the normal turbulent process within the boundary layer, thereby decreasing the transfer of momentum from the turbulent flow to the surface. The bending waves are preferably generated in a predominantly spanwise or normal direction relative to the streamwise fluid flow. In another embodiment, the bending waves enhance the turbulent process and increase the transfer of momentum between the turbulent flow and the surface. Bending wave actuators may bend the surface to generate bending waves within the surface itself. In another embodiment, actuators may generate bending waves within a separate material attached to the surface. Bending waves may also be generated within a laminar region of the boundary layer to trip the laminar region to turbulent flow and thereby energize the boundary layer.Other References
|
|
