Dimples for skin-friction drag reduction: status and perspectives
Abstract
Dimples are small concavities imprinted on a flat surface, known to affect heat transfer and also flow separation and aerodynamic drag on bluff bodies when acting as a standard roughness. Recently, dimples have been proposed as a roughness pattern that is capable to reduce the turbulent drag of a flat plate, by providing a reduction of skin friction that compensates the dimple-induced pressure drag, and leads to a global benefit. The question whether dimples do actually work to reduce friction drag is still unsettled. In this paper, we provide a comprehensive review of the available information, touching upon the many parameters that characterize the problem. A number of reasons that contribute to explaining the contrasting literature information are discussed. We also provide guidelines for future studies, by highlighting key methodological steps required for a meaningful comparison between a flat and dimpled surface in view of drag reduction.
Cite
@article{arxiv.2207.04446,
title = {Dimples for skin-friction drag reduction: status and perspectives},
author = {Federica Gattere and Alessandro Chiarini and Maurizio Quadrio},
journal= {arXiv preprint arXiv:2207.04446},
year = {2022}
}