A Note on the Effect of Diffusion Fields on the Laminar Boundary Layer
John W. Smith · Journal of the aeronautical sciences. [REQUEST TITLE] · 1953
Eq. (12) shows that the effect of an axial velocity through the duct is to reduce the resonant organ pipe frequency by a factor of (1 — M) . This result was also derived by Trimmer using an analysis based on the acoustic impedance of pipes, and it was stated by Fenn, Forney, and Garmon. The effect of an axial velocity through the duct on the end correction associated with an open end pipe has not been investigated. However, one might expect the usual correction factor to be increased as a result of the flow out of the duct. Thus, an effectively longer duct would be established, and correspondingly a still further decrease in resonant frequency would result.