Aerodynamic Study of the Effect of Span of Internal Vortex Generators 2019-01-1891
Vortex generators are aerodynamic devices generally used to delay local air separation and stalling. Conventional vortex generators are external and located normal to the surface with a yaw angle against the flow. However, external vortex generators lead to high momentum loss in the boundary layer, producing inefficient vortices which separate from the surface. They hence do not reenergise the boundary layer to a large extent, in order to allow for delayed flow separation. In order to reduce this loss, internal vortex generators may be used. The effect of internal vortex generators has been investigated on a NACA 0012 airfoil using the Computational Fluid Dynamics software ANSYS Fluent. As the effect of a vortex on the boundary layer is inherently three-dimensional, the numerical analysis of an internal vortex generator is limited to a three-dimensional simulation of the flow. The aerodynamic impact of internal vortex generators at Reynolds Number between 1,000,000 and 5,000,000 has been studied and compared against external vortex generators. Further, a parametric study has been carried out by varying the span between vortex generators between 3H and 8H, H being the height of the boundary layer. An appropriate span distance between consecutive vortex generators is hence obtained.
Pranav Bahl, B B Arora, Vishesh Kashyap, Sourajit Bhattacharjee