Excitation of instabilies in a Blasius boundary layer by surface vibration

Here we have demonstrated that small amplitude vibration can artificially excite both two dimensional (2D) and three (3D) instability modes. The 2D modes were typical of Tollmien–Schlichting (TS) waves provided the frequency excitation lies within unstable region neutral stability predicted by modal linear theory. However, even if mechanically forced mode was stable bounds curve harmonics generated non-linear response flow could develop as Further analysis streamwise spanwise evolution identified from temporal Fourier transform confirmed presence 3D excited due to nature shape deflection vibrating panel which not uniform in direction. effect non-uniformity be increased activating motors along forcing a combination motors, strong interaction with led reduction growth rate TS wave far-field despite higher initial perturbation larger number motors.