Experimental investigation of the aerodynamic stability of the “Endless Column”, Romania

Wind tunnel tests have been performed on several models of the “Endless Column”, a 30 m tall sculpture, created by C. Brancusi in 1938. In spite of its slenderness, the Column, located in Targul Jiu, Romania, has shown a great stability against wind. In order to clarify if the symmetric, original shape has influence upon its stability, we have carried out tests on section models of “Endless Column” shape (EC models) and square shape (SQ models), of various Sc numbers. Across-wind response was determined in smooth flow for wind speeds in wind tunnel of 1–10 m/s (Re=4000–46,000) for angles of attack 0°, 10° and 45°. Furthermore, an aerolastic full model was created and tests under smooth and turbulent flow conditions were performed for angles of attack between 0° and 45°. For low wind speeds, in the area of vortex-induced vibrations, the EC models had similar response with the SQ models; however, for higher wind speeds the EC models proved to be more stable. Based on measurements of aerodynamic drag and lift coefficients and by a verification of Glauert den Hartog criterion, it could be concluded that is a very low possibility for EC model to encounter galloping; for extremely high wind speeds though, this might not be impossible.