Abstract
An improvement of the digital noise filter is attempted aimed at improving the system for the feedforward control of instability waves in a transitional flat-plate boundary layer. The older control method using the Chebyshev type filter had difficulty controlling the instability waves of plural frequencies. An Inverse Chebyshev type filter is adopted as a noise filter and its characteristics are compared to the Chebyshev type filter. The results show that the Inverse Chebyshev filter can ease the deformation of wave signals compared to the Chebyshev type filter.
