| Texto completo | |
| Autor(es): |
Assi, G. R. S.
;
Orselli, R. M.
;
Silva-Ortega, M.
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF FLUIDS AND STRUCTURES; v. 89, p. 12-pg., 2019-08-01. |
| Resumo | |
The present work investigates the suppression of vortex shedding of a circular cylinder of diameter D surrounded by a polar array 8 rotating wake-control cylinders of a considerably smaller diameter d/D = 0.05. A numerical approach was employed to simulate the laminar flow at a Reynolds number of 100. The governing equations were discretised by the finite volume method for a two-dimensional computational domain. The main varying parameter was the rotation speed of the control cylinders, measured as a fraction of the incoming flow speed. A controlled wake (one without alternating vortices) was achieved when the tangential velocity at the surface of the control cylinders was greater than 3 times the free stream velocity. A significant reduction of the overall drag coefficient and mitigation of the unsteady hydrodynamic forces acting on the system were observed as rotation was increased. Given enough rotation, a negative mean drag (thrust) was achieved. The power spent to rotate the 8 control cylinders appeared to be higher than the power-loss associated with the mean drag of a bare cylinder. While still working with an active, open-loop control system, this investigation supports the development of a closed-loop wake-control device for offshore applications. (C) 2019 Elsevier Ltd. All rights reserved. (AU) | |
| Processo FAPESP: | 14/50279-4 - Brasil Research Centre for Gas Innovation |
| Beneficiário: | Julio Romano Meneghini |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa Centros de Pesquisa Aplicada |
| Processo FAPESP: | 11/00205-6 - Desenvolvimento de métodos de supressão de vibrações induzidas pelo escoamento em estruturas oceânicas |
| Beneficiário: | Gustavo Roque da Silva Assi |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |