The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
David Zimcik - One of the best experts on this subject based on the ideXlab platform.
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optimization of piezoelectric Actuator Configuration on a flexible fin for vibration control using genetic algorithms
Journal of Intelligent Material Systems and Structures, 2007Co-Authors: Andrew A Rader, Fred F Afagh, Aghil Yousefikoma, David ZimcikAbstract:This study presents a novel approach to optimizing the Configuration of piezoelectric Actuators for vibration control of a flexible aircraft fin. The fitness (cost) function for optimization using a genetic algorithm is derived directly from the frequency response function (FRF) obtained from a finite element model of the fin. In comparison to existing approaches, this method allows optimization on much more complex geometries where the derivation of an analytical fitness function is prohibitive or impossible. This technique is applied to two optimization problems for vibration control of the fin. First, the position of a single Actuator is optimized anywhere within a judiciously pre-determined area of the fin using a genetic algorithm for polynomial surface fitting of the FRF in order to obtain a continuous fitness function. Next, the Configuration of a pre-determined number of up to 48 separate Actuators is optimized within the same area. The optimization approach is verified against experimental result...
Fulvio Scarano - One of the best experts on this subject based on the ideXlab platform.
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control of vortex shedding from a blunt trailing edge using plasma Actuators
Experimental Thermal and Fluid Science, 2013Co-Authors: Giovanni Nati, Marios Kotsonis, Sina Ghaemi, Fulvio ScaranoAbstract:Abstract An experimental investigation on the use of plasma Actuators for vortex shedding suppression is performed. The vortex shedding phenomenon at the blunt trailing edge of an elongated D-shaped body is specifically investigated. The study is focused on the laminar boundary layer regime on an elongated D-shaped flat plate of 12 mm thickness at free-stream velocity up to approximately 10 m/s. Dielectric barrier discharge plasma Actuators are utilized in several geometrical Configurations at the trailing edge of the plate and are operated in continuous and pulsed mode. Several operational parameters such as applied voltage, carrier and pulse frequency and duty cycle are investigated. Results reveal that tangential actuation both in the downstream or upstream direction yields very limited effects on the coherent organization in the wake. Instead, symmetrical actuation from the base edges towards the wake centerline, proved to be very effective prompting a more detailed study of this Actuator Configuration. At external flow conditions, the reduction of the Karman wake component is monitored by the modal energy spectrum obtained from proper orthogonal decomposition of PIV data in the stream-wise/wall-normal plane of the developing wake region. The suppression of coherent vortex shedding is further ascertained with time-resolved visualizations obtained by high-speed PIV and spectral analysis conducted with hot-wire anemometry. In order to gain a complete understanding of the forcing mechanism, the velocity field induced by this Actuator Configuration is additionally investigated by means of high-speed PIV measurements conducted in initially quiescent flow. It is verified that the suppression mechanism involves the breakup of communication between the two shear layers simultaneously to moderate momentum addition into the recirculation area.
Andrew A Rader - One of the best experts on this subject based on the ideXlab platform.
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optimization of piezoelectric Actuator Configuration on a flexible fin for vibration control using genetic algorithms
Journal of Intelligent Material Systems and Structures, 2007Co-Authors: Andrew A Rader, Fred F Afagh, Aghil Yousefikoma, David ZimcikAbstract:This study presents a novel approach to optimizing the Configuration of piezoelectric Actuators for vibration control of a flexible aircraft fin. The fitness (cost) function for optimization using a genetic algorithm is derived directly from the frequency response function (FRF) obtained from a finite element model of the fin. In comparison to existing approaches, this method allows optimization on much more complex geometries where the derivation of an analytical fitness function is prohibitive or impossible. This technique is applied to two optimization problems for vibration control of the fin. First, the position of a single Actuator is optimized anywhere within a judiciously pre-determined area of the fin using a genetic algorithm for polynomial surface fitting of the FRF in order to obtain a continuous fitness function. Next, the Configuration of a pre-determined number of up to 48 separate Actuators is optimized within the same area. The optimization approach is verified against experimental result...
Aghil Yousefikoma - One of the best experts on this subject based on the ideXlab platform.
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optimization of piezoelectric Actuator Configuration on a flexible fin for vibration control using genetic algorithms
Journal of Intelligent Material Systems and Structures, 2007Co-Authors: Andrew A Rader, Fred F Afagh, Aghil Yousefikoma, David ZimcikAbstract:This study presents a novel approach to optimizing the Configuration of piezoelectric Actuators for vibration control of a flexible aircraft fin. The fitness (cost) function for optimization using a genetic algorithm is derived directly from the frequency response function (FRF) obtained from a finite element model of the fin. In comparison to existing approaches, this method allows optimization on much more complex geometries where the derivation of an analytical fitness function is prohibitive or impossible. This technique is applied to two optimization problems for vibration control of the fin. First, the position of a single Actuator is optimized anywhere within a judiciously pre-determined area of the fin using a genetic algorithm for polynomial surface fitting of the FRF in order to obtain a continuous fitness function. Next, the Configuration of a pre-determined number of up to 48 separate Actuators is optimized within the same area. The optimization approach is verified against experimental result...
Fred F Afagh - One of the best experts on this subject based on the ideXlab platform.
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optimization of piezoelectric Actuator Configuration on a flexible fin for vibration control using genetic algorithms
Journal of Intelligent Material Systems and Structures, 2007Co-Authors: Andrew A Rader, Fred F Afagh, Aghil Yousefikoma, David ZimcikAbstract:This study presents a novel approach to optimizing the Configuration of piezoelectric Actuators for vibration control of a flexible aircraft fin. The fitness (cost) function for optimization using a genetic algorithm is derived directly from the frequency response function (FRF) obtained from a finite element model of the fin. In comparison to existing approaches, this method allows optimization on much more complex geometries where the derivation of an analytical fitness function is prohibitive or impossible. This technique is applied to two optimization problems for vibration control of the fin. First, the position of a single Actuator is optimized anywhere within a judiciously pre-determined area of the fin using a genetic algorithm for polynomial surface fitting of the FRF in order to obtain a continuous fitness function. Next, the Configuration of a pre-determined number of up to 48 separate Actuators is optimized within the same area. The optimization approach is verified against experimental result...