Active Control of Kelvin-Helmholtz Waves

Aeroacoustic Research in Europe: The Ceas-Asc Report on 1998 Highlights

“…This linear system is not causal, but there are causal systems with a transfer function which di!ers only for small frequencies. It can be shown that this system cancels not only the incident Kelvin}Helmholtz waves but also the disturbances generated by point sources, provided that they are in a $45-sector upstream of the sensor}actuator position [14]. (W. MoK hring and J.E.…”