The analysis has been performed on behalf of ABB Ventilation Products AB (now Fläkt Woods AB). The fan is modelled by shell and solid elements.

The vibration frequencies have been calculated for various rotationary speeds, in the working range of the fan, as well as for stationary fan. Stress stiffening due to centrifugal forces is included in the analysis.

The figure shows one of the calculated vibration modes.

Keywords: Fläkt Woods AB, FE analysis, PERMAS, MEDINA, modal analysis, rotor, stress stiffening