An experimental study on flow separation control of hydrofoils with leading-edge tubercles at low Reynolds number

Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

“…This manner of flow distribution is comparable to what is performed by tubercles or pattern peaks on the leading edge (Hansen et al 2011;Wei et al 2015), therefore, it can be concluded that each peak of the pattern can be used as a passive flow control similar to a counter-rotating vortex generator. …”

“…This may delay the boundary layer separation, which is favorable in aerodynamics. Additionally, the heat transfer rate may also increase due to the mixing enhanced by the streamwise counter-rotating vortices particularly near the wall zone (Webb and Kim 2005). Vortex generators (VGs) are frequently utilized to generate streamwise vortices by making discontinuity and shear forces in the flow (Lin et al 1991;Godard and Stanislas 2006).…”

“…It was shown that the serration size is more effective as the Reynolds number increases such that the larger serrations led to lift reduction at all angles of attack. All the above studies involved the generation of streamwise vortices within the boundary layer via leading edge variations which are functionally comparable to conventional vortex generators and delta-wings due to similar manner in vortex formation and characteristics (Hansen et al 2011;Wei et al 2015). To have a better picture of how the leading edge variations generate the streamwise vortices, a set of flow visualizations were carried out by Hasheminejad et al (2014).…”

Numerical Investigation on Flow Separation Control of Low Reynolds Number Sinusoidal Aerofoils

“…The two-equation Shear Stress Transport (SST) turbulence model was implemented in the current investigation. The current work aims to further investigate the studies conducted by Wei et al 2 by looking into the wall shear streamlines, vector plots as well as iso-surface contours of shear at the vicinity of the aerofoil. The present investigations also extend the study conducted by Joy et al 7 by utilizing a structured hexahedral grid for the simulations.…”

“…Studies into its operation at low Reynolds numbers have spurred particular interests recently, due to their intriguing design characteristics and effects on flow separation behavior and vortex generation 2,3 . This research area draws its inspirations from the morphology of humpback whales which possess exceptional maneuvering and turning ability at higher velocities, especially when they are approaching their preys.…”