Vortex Excitation of Metal Bellows

The present paper extends the results presented in an earlier paper, and pertains to the prediction of vibratory amplitudes and stress levels resulting from flow-induced vibrations of metal bellows. Included is visual verification of the vortex shedding-bellows convolution coupling phenomena. Two methods for predicting flow excitation amplitudes are described. One method, called a “Stress Indicator” method is a simplification of the other, and allows rapid estimates of bellows dynamic stress values. This simplified method is complemented by a plot of “Stress Indicator” versus number of cycles to failure, obtained from experimental data for actual bellows failures. The influences of bellows damping and acoustical resonances are discussed.