Abstract
This paper reports wind tunnel tests of a low Reynolds number vehicle model. The experiments were conducted
at 1:5 105 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.
at 1:5 105 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.
| Original language | English |
|---|---|
| Title of host publication | 24th ABCM International Congress of Mechanical Engineering |
| Publisher | ABCM |
| Edition | 24 |
| DOIs | |
| Publication status | Published - 2017 |
| Externally published | Yes |
| Event | 24th ABCM International Congress of Mechanical Engineering, COBEM 2017 - Curitiba, Brazil Duration: 3 Dec 2017 → 8 Dec 2017 Conference number: 24 |
Conference
| Conference | 24th ABCM International Congress of Mechanical Engineering, COBEM 2017 |
|---|---|
| Abbreviated title | COBEM 2017 |
| Country/Territory | Brazil |
| City | Curitiba |
| Period | 3/12/17 → 8/12/17 |
Keywords
- High-lift low Reynolds number airfoil
- laminar separation bubble
- Eppler 423 airfoil
- wind tunnel tests