Accession Number : AD1016724


Title :   Flow Control


Descriptive Note : Technical Report,24 Jan 2010,24 Jan 2013


Corporate Author : KC Engineering, Inc Colorado Springs United States


Personal Author(s) : Fagley,Casey


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/1016724.pdf


Report Date : 08 Apr 2013


Pagination or Media Count : 140


Abstract : Contract FA7000-10-2-0003 was in direct response to Broad Agency Announcement (BAA) withthe Aeronautics Laboratory at the United States Air Force Academy. The announcement in the BAA in which this contract was directly related is quoted from the BAA as, Current research strengths include several complementary thrusts. Closed loop flow control efforts focus on aero-optic and energy extraction, with extensive effort in the development of automatic control algorithms and techniques, experimental flow control methodologies and CFD simulations. Work under this contract produced new, innovative and theoretical methods for developing control algorithms. In particular artificial neural networks coupled with direct adaptive control was a new innovative solution for achieving successful control of very high dimensional, non linear dynamical systems. This control technique which is described in detail throughout this manuscript was successfully applied to a wide variety of flows. This flow control approach proved to successfully reduce the drag on a circular cylinder by decreasing the amount of energy in the von Karman street, mitigate optical abberations through a free unstable shear layer, as well as regulate and exploitthe asymmetric vortex formulation behind an axi-symmetric bluff body at high incidence. Each of these flow control applications had inherently different dynamics including periodic vortex shedding, separated free unstable shear layers, and combinations thereof, which demanded alarge amount of robustness from a control design perspectives. Applications and demonstration of successful feedback flow control where shown both experimentally and computationally. This manuscript goes into great detail on the theoretical approach which has been adopted by the USAFA flow control group and then details the applications to each of the fluid dynamics problems.The report then summarizes the business portion of the contractual agreement.


Descriptors :   control theory , flow fields , algorithms , computational fluid dynamics , simulations navier stokes equations , galerkin method


Distribution Statement : APPROVED FOR PUBLIC RELEASE