Abstract
A root‐locus solution for the frequency lock‐in problem has been obtained for a wall‐mounted cavity in turbulent flow, oscillating at Helmholtz or depth‐mode resonance. For case where acoustic wavelength is large compared to cavity mouth dimension, feedback takes the form of a simple transverse modulation by acoustic standing wave in the cavity. System gain is found to derive from periodic deflection of volume flow into the cavity from external fluid as in Type‐I organ pipe oscillation. Unlike the organ pipe case, however, only downstream interface waves are observed, there being no boundary condition imposed on the slope of the interface at leading edge. Phase velocity of the interface wave is obtained from mean stream velocity profile, using linearized instability theory. System is capable of oscillation at frequencies both above and below resonance, the exact resonant condition being characterized by a stream‐wise slot width (M‐1/4) times the interface wavelength, where M is an integer. From a knowledge of the nonlinear orifice resistance characteristic, oscillation amplitude can be predicted as a function of slot width. [Work supported by a GHR contract with the Naval Sea Systems Command, administered by the David Taylor Naval Ship Research and Development Center, Carderock, Maryland.]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
