Journal of Fluid Mechanics

Aerodynamic excitation of the harmonium reed

Arthur O. St  Hilaire a1p1, Theodore A.  Wilson a1 and Gordon S.  Beavers a1
a1 Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, Minnesota

Article author query
hilaire ao   [Google Scholar] 
wilson ta   [Google Scholar] 
beavers gs   [Google Scholar] 


An investigation of the mechanism responsible for the self-excited oscillations of a harmonium reed is presented. Experiments show that the amplitude of vibration of the reed grows exponentially, and measurements of the growth rate as a function of the flow past the reed are reported. Flow visualization studies lead to the conclusion that jet or wake instability is not important in exciting the reed vibration. An analysis of the flow around the reed as an unsteady potential flow results in the evaluation of the aerodynamic forces exciting the reed. The analysis shows that the pressure which excites the reed motion is of the order of $\rho U_0\dot{a}$, where U0 is the flow velocity and $\dot{a}$ is the reed velocity.

(Published Online March 29 2006)
(Received February 25 1971)

p1 Present address: Mechanical Engineering Department, Tufts University.