an experimental study was carried out on the wake of a cylinder on the back of which a plate is installed parallel to the fluid flow, with different terminal angles, where the reynolds number is 50000. at the end of the plate, blades with the height of 0.25 equal to the cylinder diameter and with 45, 90 and 135 degrees angle from the horizon, are installed where the cylinder diameter is equal t...

this paper presents efflux time experiments performed in the absence and presence of aqueous solutions of drag reducing agents (dras) when a liquid is emptied from a large open cylindrical storage tank through an exit piping system. the drag reducing agents studied are dodecyl benzene sulfonate anionic surfactant and a mixed solution of surfactant and sodium chloride counter ion. the variables ...

(173 articles) fluid mechanics collections Articles on similar topics can be found in the following Email alerting service here in the box at the top right-hand corner of the article or click Receive free email alerts when new articles cite this article-sign up Turbulence physics responsible for high skin-friction drag in turbulent boundary layers is first reviewed. A self-sustaining process of...

Abstract Turbulence drag reduction is of great significance for the range increase hypersonic flight vehicles. The proposed velocity-temperature coupling control method (Liu et al, Phys Rev Fluids 6:044603, 2021) further extended to turbulent boundary layer. Direct numerical simulation results four comparative cases show that heated wall blowing achieves a rate 10.58%, which about sum (5.27%) a...

The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and...

Over the last two decades, both experiments and simulations have demonstrated that transverse wall oscillations with properly selected amplitude and frequency can reduce turbulent drag by as much as 40 %. In this paper, we develop a model-based approach for designing oscillations that suppress turbulence in a channel flow. We utilize eddyviscosity-enhanced linearization of the turbulent flow wi...