Conditions for the excitation of core rotation in a mechanical vortex device

It is established that aerodynamic drag alone is insufficient to induce forced rotation of a bearing-supported axial core in a mechanical vortex device at an input-flow pressure of up to 0.7 MPa. A necessary condition for the onset of core rotation is the excitation of bending and axial precession of the cantilever-supported core. In the absence of a mechanical contact between the core and expansion chamber of the vortex device, the direction of core rotation is the same as that of the airflow vortex. Forced rotation in the counter direction starts under conditions of dynamic bending that leads to the mechanical contact and rolling of the core over the surface of the expansion chamber.