TY - JOUR TI - Influence of running conditions on resonant oscillations in fresh-air ventilator blades used in thermal power plants AU - Tasić Milan B AU - Mitrović Radivoje M AU - Popović Predrag S AU - Tasić Marko M JN - Thermal Science PY - 2009 VL - 13 IS - 1 SP - 139 EP - 146 PT - Article AB - High frequency cyclic load of fresh air supply to ventilator blades in thermo energetic facilities can cause the occurrence of fretting in the pressed overlap of ventilator shaft and socket. These loads can be generated by the resonant oscillations of ventilator blades and thermal residual stress due to welding. To prevent running in resonant conditions, the manufacturer of the ventilator defined a procedure of adjusting blades natural frequency in the process of production, as well as period control during exploitation period. The numerical simulations and the accelerations measured and presented in this paper, enabling analysis of mass changes and rotation rate effects on resonant oscillations occurrence in fresh air ventilator.