Reduction of flow-induced vibration by means of structure elasticity control

Flow-induced vibration is one of frequent issues in engineering. There are usually some dominant frequencies in excitation. These frequencies either are predetermined by incoming flow, or appear due to vortex shedding from a structure. There are also not many structural resonances within the band of dominant frequencies. The problem is to avoid their coincidences. Many machinery elements can be aerodynamically considered as foils. The foil response on periodically flow excitations can be analyzed in framework of potential theory, but for the considered problem, the surface deformations must be taken into account. Elastic beam is selected as the foil structural model. Substantial tuning the beam structural resonances can be effected by non-uniform distribution of the beam elasticity. As shown by numerical analysis for several types of foil and flow excitation, such tuning is especially successful for second structural resonance. It allows significant reducing of amplitude response or changing of the resonance frequency.