Turbulent Drag Reduction in Flows past a Flat Plate with Microgrooves

Paulo Arthur Beck¹; Horácio Antonio Vielmo¹

¹ UFRGS

doi:10.20906/CPS/COB-2015-0790

Resumo

The potential in drag reduction of turbulent flows over a flat plate with streamwise aligned microgrooves is investigated. For this purpose, the connection between the anisotropy of the Reynolds stresses and the drag reduction effect is presented, and a model is developed in order to estimate the drag reduction potential according to flow and geometrical settings. The Navier-Stokes transport equations particularized for incompressible flows are used to describe the fluid motion, and the turbulence quantities are evaluated using the linear pressure-strain Reynolds stress transport model. The quantities are estimated using the Finite -Volume method, which is applied to a set of grids with different refinement levels. After validating the numerical method against the predictions of the proposed model, and the theoretical and DNS estimates available in the literature, the authors discuss the drag reducing effect by examining the state of turbulence in the microgrooves, also providing an assessment on the anisotropy of the Reynolds Stresses inside, near and outside the grooves.

Palavras-chave: drag reduction; microgrooves; turbulence