Flutter-Mill: a New Energy-Harvesting Device

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that in this case the total work done by fL is positive, as shown in Fig. 4(d). Fig. 5: When flutter takes place, the positive/negative (P/N) work done by the fluid load fL at various locations along the length of the plate: (a) , , (b) , , (c) , , (d) , , (e) , , and (f) , . The other parameters of the system are: , and . Note that, is used for the cases and ; while, for the other cases , and , is used. The energy transfers at 40 locations (every 5 panels in the case of and every 10 panels when ) are recorded. The distribution of positive/negative is also examined for various systems with different values of , as shown in Fig. 5. It should be mentioned that different values of are used for individual cases of for the purpose of obtaining flutter motions (in particular, is so chosen about 10% above the corresponding critical point ). It can be seen in Fig. 5 that the distribution of positive/negative depends on . When is large, say or 5, higher modes become important in the dynamics [1], and the distribution of positive/negative has a complicated pattern. It should be mentioned that the distribution of the positive/negative also depends on the value of , as one may see in Figs. 5(b) and (c); however, it has
een shown that this variation normally occurs at locations close to the fixed and free ends of the plate, where the level of energy transfer is much lower than elsewhere (refer to Fig. 4(b)). 4. The design of the flutter-mill 4.1. Determination of key design parameters It has been shown that, at different sections of the plate, the energy transfer may be from the fluid flow to the plate or vice versa. Therefore, the conductors embedded in the flexible plate should be correspondingly arranged in several sections, or say phases. Too many phases of conductor arrangement lead to difficulties in the design of the wiring scheme and the rectifier. To this end, in the light of the vibration modes of the system with various values of (see Fig. 12 of Ref. [1], also Figs. 4 and 5 in the present paper), a system with mass ratio should be considered, for which the plate vibrates in the second beam mode. Hence, only two phases of conductor arrangement are necessary. The present paper primarily considers two cases: and 0.2. In the conceptual design, dimensional parameters allow one to evaluate the performance of the device in a more Table 1: Dimensional parameters of the flutter-mills with and 0.2. Plate 1 Plate 2 Unit 1.226 1.226 kg/m 3 2840 2840 kg/m 3 h 0.5 0.5 mm L 0.58 0.232 m B 0.2 0.2 m 0.5 0.2 Fig. 6: The dynamics of the system with and the time-averaged power of the fluid load fL: (a) the bifurcation diagram, (b) the flutter frequency, and (c) the time-averaged power . The other parameters of the system are: , and .
Page 1 and 2: Flutter-Mill: a New Energy-Harvesti
Page 3 and 4: other physical parameters of the sy
Page 5: Note that is the time integral of .
Page 9 and 10: Watt power (at m/s or 43.2 km/h) fr

Flutter-Mill: a New Energy-Harvesting Device

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