Aerodynamic effects on a non-typical steel chimney 120 m high

Two identical steel chimneys, 120 m high were erected about 5 years ago. During exploitation of the chimneys, occurrence of considerable cross vibrations of the whole supporting structure and of the chimney shaft were noticed. Similar observation results were obtained for each of these chimneys. Observation results constituted the basis for carrying out a computational analysis, which aimed at determination of the causes of occurrence of this phenomenon and finding the possibility of reduction of chimney vibration. Results of these detailed analysis are presented and confronted with observation results. In order to eliminate considerable chimney vibrations caused by the described aerodynamic phenomenon, specially designed turbulizers and, subsequently, mechanical vibration dampers were applied. Effects of the treatments will be presented in the paper.