The features of 2D and 3D flow over circular cylinder with different surfaces

Bluff bodies in a gas or liquid flow are a fairly common phenomenon, which is often found in both natural and technogenic processes. Various structural elements of aerospace transport systems, pipelines, gas turbines, heat exchangers, etc. in many cases can be considered, at least qualitatively, as a two-dimensional cylinder in a flow at some angle of attack. Depending on the specific situation, it may be necessary to suppress or intensify the process of vortex generation, increase or decrease the drag coefficient of the body, decrease or increase the level of noise produced by the body in a flow. The fulfillment of these tasks is impossible without knowledge of the mechanisms of formation of the flow under the current flow regimes. In the presented study, models of circular quasi-two-dimensional or finite cylinders are used as a bluff body model. To control the flow textile materials were used which were previously studied in other works of the co-authors [1]. These materials can cover the cylinders. The change of effective diameter of the cylinders then is around 1% and is considered insignificant when textile material is applied on cylinder.