Chapter 6: 2015 Problem 10: Singing Blades of Grass

In this study, acoustic properties of the pure tone produced by a vibrating plate with in-plane tension in a uniform parallel flow is investigated theoretically and experimentally. By modifying Euler-Bernoulli beam equation combined with the mean flow theory, an explicit expression for the frequency of the pure tone is derived using eigenvalue method, in which all of the parameters can be measured in experiments. To verify the new equation, experiments have been designed to investigate the effects of the flow velocity and in-plane tension on the frequency and intensity of the sound, whose results have a good agreement with the theoretical results.