**α**=8<sup>0</sup> ± 5.5**sin**(**ωt**)<sup>0</sup>

Figure 19 illustrates the evolution of the aerodynamic coefficients with oscillation of the AoA around 80 with amplitude 5.50 and a reduced frequency of 0.026. When the angle is less than 140 , the transitional k-ω SST intermittency model was used.

**Figure 19.** Drag and lift coefficients vs. angle of attack for stall modelling

For the drag coefficient, the results are very close to experimental ones and limited hystere‐ sis appears. As for the lift coefficient, we note that the «k-ω SST intermittency» transitional turbulent model underestimates the hysteresis phenomenon. Furthermore, this model pro‐ vides results with inferior values as compared to experimental ones for increasing angle of attack and superior values for decreasing angle of attack. We, also, notice that the onset of the stall phenomenon is earlier for the «k-ω SST intermittency» model.
