Galloping stability of triangular cross-sectional bodies:: A systematic approach

One of the classical aeroelastic instabilities of slender structures is galloping, which can be characterized as a low-frequency, large-amplitude normal to the flow oscillations phenomenon. In this paper, the transverse galloping stability of triangular cross-section bodies has been systematically analyzed (up to now, most of the effort in galloping oscillation research has been concentrated on bodies with square or rectangular cross-sections). To perform such analysis, first, the Glauert-Den Hartog criterion for galloping instability was used through wind tunnel static tests. Then, another series of wind tunnel dynamic tests was realized to determine the transversal cross-section displacements as a function of the incident wind velocity. The results from these dynamic-tests are in very good agreement with the results obtained from the static ones. Finally, information on the flow morphology needed for the physical interpretation of the results was obtained by measuring the pressure distribution along the body surfaces. (C) 2007 Elsevier Ltd. All rights reserved.