Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
EXPERIMENTAL ASSESMENT OF A LOW REYNOLDS NUMBER VEHICLE
Submission Author:
Laura Botero-Bolivar , SP , Colombia
Co-Authors:
Daniel Acevedo-Giraldo, Laura Botero-Bolivar, Pedro David Bravo-Mosquera, Hernán Cerón-Muñoz, Fernando catalano
Presenter: Laura Botero-Bolivar
doi://10.26678/ABCM.COBEM2017.COB17-0690
Abstract
This paper reports wind tunnel tests of a low Reynolds number vehicle model. The experiments were conducted at 1.5x10^5 Reynolds number (Re). A Laminar Separation Bubble (LSB) was observed on the upper surface of the wing. Such a phenomenon, that occurs at low Reynolds numbers, is caused by the inability of the laminar flow to complete the transition to turbulent attached to the surface of the airfoil, therefore the laminar flow separates before its transition. The lift coefficient (CL) decreased and the drag coefficient (CD) increased by the presence of the bubble, modifying aircraft performance considerably. To guarantee the transition, two processes were carried out. On the first one, a trip was added on the upper surface and as a second alternative, the effective Reynolds number was increased. The results showed how the bubble affects the vehicle performance. Experiments were conducted at the aircraft laboratory of aerodynamics (LAE) of the São Carlos School of Engineering - University of São Paulo (EESC-USP), Brazil.
Keywords
High-lift low Reynolds number airfoil, Laminar separation bubble, Eppler 423 airfoil, wind tunnel tests.
