Investigation of mean and fluctuation characteristics of the wake flow behind cylinders fitted with textile materials

In the present paper, the results of a study of the influence of textile materials on the structure of the aerodynamic wake behind blunt-body models in the form of quasi-two-dimensional and cantilever cylinders are reported. The fabrics used were previously examined in the works by co-authors while determining the drag coefficient of a two-dimensional cylinder. The change in diameter in the latter case proved to be not more than 1%, and it was considered insignificant. The use of fabrics has made it possible to reduce the critical Reynolds number to about 2·10⁵. The two- and three-dimensional flows turned out to be similar in terms of fluctuation level, whereas some narrowing of the wake behind the cantilever cylinder occurred due to the three-dimensional structure of the flow. Based on the results of spectral analysis, complete similarity between three- and two-dimensional flows was demonstrated, both for the flow around a smooth cylinder and for the flows around cylinders fitted with textile materials.