4.2 | Simulated of the aerodynamic test of TWA
models
After
simulation by Ansys Fluent, the results were shown in the Figure 7 (b)
and (c). It shows that the trend of the l and\(\overset{\overline{}}{C_{l}/C_{d}}\) are similar.
Thel of the obtuse angle airfoil (OAA) decreases to
negative value when the corrugation number is 4, and the data don’t show
when the corrugation number of 5-8.
So,
the l and \(\overset{\overline{}}{C_{l}/C_{d}}\)are the highest when the corrugation angle is obtuse angle and the
corrugation number is 1. And thel and \(\overset{\overline{}}{C_{l}/C_{d}}\)of obtuse angle are 50.47%
and 67.68% higher than the FPA model (where corrugation number is 0) at
55 Hz, respectively. The l and\(\overset{\overline{}}{C_{l}/C_{d}}\) of obtuse angle are similar at 65
Hz and 75 Hz, which is 76.36% and 90.93% higher than the FPA model.
Furthermore, the right angle airfoil (RAA) and the acute angle airfoil
(AAA) appear the largest l and\(\overset{\overline{}}{C_{l}/C_{d}}\) when the corrugation number is 5.
Compared to the FPA model, the aerodynamic performance of the corrugated
airfoils is higher.
This
is because the corrugated airfoils can lock the vortex into the
corrugated groove at the reasonable corrugation number and corrugation
angle (Engels et al., 2020; Shahzad et al., 2017). In other words,
corrugated airfoils have better performance than the flat plate wing in
preventing large-scale flow separation and airfoil stall at lowRe .
But continuing to increase corrugation is not beneficial to improve
lift. This result show that when the number of corrugations is greater
than 5, the l and\(\overset{\overline{}}{C_{l}/C_{d}}\) begins to decrease. When there
are too many corrugations, the airflow cannot effectively transition at
the boundary layer of the trailing edge, the turbulence will be
increased, as shown in Figure 7 (d).