Figure 7
The measured and theoretically predicted flutter frequency vs. air flow velocity above the flutter onset velocity for (a) double-clamped AlN/Si belt (length × width × thickness: 10 mm × 1 mm × 21 μm), and (b) for P(VDF-TrFE) (length × width × thickness: 22 mm × 1.2 mm × 20 μm) under two prestress conditions (T0 = constant ≈ 0.07 N and 0.21 N). The uncertainty of theoretically predicted data for “stiff” belt is presented in area filled in grey color, where such uncertainty comes from the difference between individual AlN/Si belt. The data indicate that the flutter frequency is rarely constant for the “stiff” material based belt as the air flow velocity increases, while the frequency scales almost linearly with the air flow velocity, and flutter frequency are modulated by prestress for “flexible” material.
