The force generation mechanism of lifting surfaces with flow separation

Near Wake Hydrodynamics and Structural Design of a Single Foil Cycloidal Rotor in Regular Waves

“…Figure 12 shows that the loading on the foil remains relatively constant for the case of attached flow. This is in agreement with the flow field observations presented in figure 9, in which the flow around the foil remains largely Although we only have information from four azimuthal positions of the flow field around the foil, at 𝜃 = 0 • , 𝜃 = 90 • , 𝜃 = 180 • and 𝜃 = 270 • , the trend in 𝑅 can be explained through these flow field snapshots and the impulse of a vortex pair [8,36,47]. As evidenced in figure 9, a clear vortex pair is formed at 𝜃 = 90 • , whilst the pair is at its infant state at 𝜃 = 0 • .…”

“…Hence, both terms, circulation growth and advection velocity of the LEV explain the increase in 𝑅 of the foil [36,47]. This preprint research paper has not been peer reviewed.…”

“…However, the presence of the LEV influences and reduces any bound circulation on the foil [6,3,47]. As such, the force decreases in the vicinity of this azimuthal angle.…”

“…Contrary to the circulation zone in figure 10a, the LEV in figure 10b is mirrored by a TEV of opposite circulation. As such, according to impulse theory, the vortex pair will have an instantaneous influence in the force time stamp of the foil through growth rate of circulation ( Γ) and through the advection velocity of the LEV ( ḋ) [36,47].…”

Use of streamnormal forces within an array of tidal power harvesters

“…The agreement between the Navier-Stokes solution and potential flow theory suggests that the solution is effectively Reynolds number independent. In the Navier-Stokes solutions, vorticity is generated through the harvester region because a streamwise force is exerted [ 26 ]. If the Reynolds number is sufficiently high, the effect of the Reynolds number is only a marginal increase in the wake diffusion.…”