The effect of grazing flow on the impedance of the Helmholtz resonator
Abstract
A theoretical model for an acoustically excited Helmholtz resonato in a steady grazing flow is presented for the case of low excitation frequency and amplitude, and moderate grazing flow Mach number. The analysis is based on he two-dimensional linearized inviscid equation of motion. The case with razing flow was solved using the Green's function technique. The Kutta condition at the upstream edge of the slit and a displacement thickness wave on the downstream wall was introduced to mathematically model the effect of vortex shedding at the sharp edges of the slit. This vortex shedding provides the mechanism by which acoustic energy is converted to vortical energy which is carried away by the grazing flow. The result of the limiting case of vanishingly small grazing velocity also agrees with the result of the case without grazing flow.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1984
- Bibcode:
- 1984PhDT.........8N
- Keywords:
-
- Acoustic Impedance;
- Grazing Flow;
- Helmholtz Resonators;
- Slits;
- Vortices;
- Equations Of Motion;
- Grazing Flow;
- Green'S Functions;
- Mach Number;
- Fluid Mechanics and Heat Transfer