Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform vis... more Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform viscous flow was simulated by using the immersed boundary method (IBM) along with low-speed wind tunnel experimentation. The flag in the wake of the cylinder was strongly influenced by the vortices shed from the upstream cylinder under the vortex-vortex and vortex-body interactions. Geometric and flow parameters were optimized for the flexible flag subjected to passive flapping. The influence of length and bending coefficient of the flexible flag, the diameters (D) of the cylinder and the streamwise spacing between the cylinder and the flag, on the energy generation was examined. Constructive and destructive vortex interaction modes, unidirectional and bidirectional bending and the different flapping frequency were found which explained the variations in the energy of the downstream flag. Voltage output and flapping behavior of the flag were also observed experimentally to find a more direct relationship between the bending of the flag and its power generation.
The effect of base suction on flapping and energy harvesting through the piezoelectric membrane i... more The effect of base suction on flapping and energy harvesting through the piezoelectric membrane in the wake of a cylindrical bluff body is studied in this paper by carrying out a series of wind tunnel experiments. The effect of S/D (ratio of the distance between the cylinder and membrane to the cylinder diameter), L/D (ratio of the membrane length to the cylinder diameter), and flow speed on the flapping dynamics and energy generation from the polyvinylidene fluoride membrane placed behind the bluff body was studied. Different flapping modes were found from optimal coupling to fully deformed. The flapping motion of the membrane was determined by using a high-speed camera, and an oscilloscope was used for the measurement of the generated voltages. Also, the flapping dynamics and output voltages were extensively studied in the sub and post-critical regions by varying the S/D ratio, L/D ratio, and flow velocity. An increase of 38% in energy harvesting is observed when the piezomembrane was placed at L/D ¼ 1 and S/D ¼ 2 with free stream velocity U ¼ 10 m/s. An increase or decrease in voltages is attributed to the observation that the amount of harvested energy changes by varying the stated parameters. Optimum energy can be harvested by fine-tuning of flow and geometrical parameters and adjusting the piezoelectric flag in the specified range. Published under license by AIP Publishing. https://doi.
Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform vis... more Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform viscous flow was simulated by using the immersed boundary method (IBM) along with low-speed wind tunnel experimentation. The flag in the wake of the cylinder was strongly influenced by the vortices shed from the upstream cylinder under the vortex-vortex and vortex-body interactions. Geometric and flow parameters were optimized for the flexible flag subjected to passive flapping. The influence of length and bending coefficient of the flexible flag, the diameters (D) of the cylinder and the streamwise spacing between the cylinder and the flag, on the energy generation was examined. Constructive and destructive vortex interaction modes, unidirectional and bidirectional bending and the different flapping frequency were found which explained the variations in the energy of the downstream flag. Voltage output and flapping behavior of the flag were also observed experimentally to find a more direct relationship between the bending of the flag and its power generation.
The effect of base suction on flapping and energy harvesting through the piezoelectric membrane i... more The effect of base suction on flapping and energy harvesting through the piezoelectric membrane in the wake of a cylindrical bluff body is studied in this paper by carrying out a series of wind tunnel experiments. The effect of S/D (ratio of the distance between the cylinder and membrane to the cylinder diameter), L/D (ratio of the membrane length to the cylinder diameter), and flow speed on the flapping dynamics and energy generation from the polyvinylidene fluoride membrane placed behind the bluff body was studied. Different flapping modes were found from optimal coupling to fully deformed. The flapping motion of the membrane was determined by using a high-speed camera, and an oscilloscope was used for the measurement of the generated voltages. Also, the flapping dynamics and output voltages were extensively studied in the sub and post-critical regions by varying the S/D ratio, L/D ratio, and flow velocity. An increase of 38% in energy harvesting is observed when the piezomembrane was placed at L/D ¼ 1 and S/D ¼ 2 with free stream velocity U ¼ 10 m/s. An increase or decrease in voltages is attributed to the observation that the amount of harvested energy changes by varying the stated parameters. Optimum energy can be harvested by fine-tuning of flow and geometrical parameters and adjusting the piezoelectric flag in the specified range. Published under license by AIP Publishing. https://doi.
Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform vis... more Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform viscous flow was simulated by using the immersed boundary method (IBM) along with low-speed wind tunnel experimentation. The flag in the wake of the cylinder was strongly influenced by the vortices shed from the upstream cylinder under the vortex-vortex and vortex-body interactions. Geometric and flow parameters were optimized for the flexible flag subjected to passive flapping. The influence of length and bending coefficient of the flexible flag, the diameters (D) of the cylinder and the streamwise spacing between the cylinder and the flag, on the energy generation was examined. Constructive and destructive vortex interaction modes, unidirectional and bidirectional bending and the different flapping frequency were found which explained the variations in the energy of the downstream flag. Voltage output and flapping behavior of the flag were also observed experimentally to find a more direct relationship between the bending of the flag and its power generation.
The effect of base suction on flapping and energy harvesting through the piezoelectric membrane i... more The effect of base suction on flapping and energy harvesting through the piezoelectric membrane in the wake of a cylindrical bluff body is studied in this paper by carrying out a series of wind tunnel experiments. The effect of S/D (ratio of the distance between the cylinder and membrane to the cylinder diameter), L/D (ratio of the membrane length to the cylinder diameter), and flow speed on the flapping dynamics and energy generation from the polyvinylidene fluoride membrane placed behind the bluff body was studied. Different flapping modes were found from optimal coupling to fully deformed. The flapping motion of the membrane was determined by using a high-speed camera, and an oscilloscope was used for the measurement of the generated voltages. Also, the flapping dynamics and output voltages were extensively studied in the sub and post-critical regions by varying the S/D ratio, L/D ratio, and flow velocity. An increase of 38% in energy harvesting is observed when the piezomembrane was placed at L/D ¼ 1 and S/D ¼ 2 with free stream velocity U ¼ 10 m/s. An increase or decrease in voltages is attributed to the observation that the amount of harvested energy changes by varying the stated parameters. Optimum energy can be harvested by fine-tuning of flow and geometrical parameters and adjusting the piezoelectric flag in the specified range. Published under license by AIP Publishing. https://doi.
Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform vis... more Inspired by the energy harvesting eel, a flexible flag behind a D-shape cylinder in a uniform viscous flow was simulated by using the immersed boundary method (IBM) along with low-speed wind tunnel experimentation. The flag in the wake of the cylinder was strongly influenced by the vortices shed from the upstream cylinder under the vortex-vortex and vortex-body interactions. Geometric and flow parameters were optimized for the flexible flag subjected to passive flapping. The influence of length and bending coefficient of the flexible flag, the diameters (D) of the cylinder and the streamwise spacing between the cylinder and the flag, on the energy generation was examined. Constructive and destructive vortex interaction modes, unidirectional and bidirectional bending and the different flapping frequency were found which explained the variations in the energy of the downstream flag. Voltage output and flapping behavior of the flag were also observed experimentally to find a more direct relationship between the bending of the flag and its power generation.
The effect of base suction on flapping and energy harvesting through the piezoelectric membrane i... more The effect of base suction on flapping and energy harvesting through the piezoelectric membrane in the wake of a cylindrical bluff body is studied in this paper by carrying out a series of wind tunnel experiments. The effect of S/D (ratio of the distance between the cylinder and membrane to the cylinder diameter), L/D (ratio of the membrane length to the cylinder diameter), and flow speed on the flapping dynamics and energy generation from the polyvinylidene fluoride membrane placed behind the bluff body was studied. Different flapping modes were found from optimal coupling to fully deformed. The flapping motion of the membrane was determined by using a high-speed camera, and an oscilloscope was used for the measurement of the generated voltages. Also, the flapping dynamics and output voltages were extensively studied in the sub and post-critical regions by varying the S/D ratio, L/D ratio, and flow velocity. An increase of 38% in energy harvesting is observed when the piezomembrane was placed at L/D ¼ 1 and S/D ¼ 2 with free stream velocity U ¼ 10 m/s. An increase or decrease in voltages is attributed to the observation that the amount of harvested energy changes by varying the stated parameters. Optimum energy can be harvested by fine-tuning of flow and geometrical parameters and adjusting the piezoelectric flag in the specified range. Published under license by AIP Publishing. https://doi.
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Papers by Malik Usman