Head-on parallel blade-vortex interaction

Adaptive Euler simulations of airfoil–vortex interaction

“…It is found in Figure 5 that compared with multiblock grid Navier-Stokes results in Reference [20] based on nearly 193 000 points, our adaptive Euler computation with only about 32 800 points gives much steeper slopes of the pressure and much larger peak values due to much less numerical diffusion inherent in the computation. Since the viscous terms are not included in our computation, the predicted slopes of pressure in the present computation are even slightly steeper than the experimental data.…”

“…On the other hand, the viscous effect over the upper surface can be neglected. Figure 6 compares the computational density snapshots with the experimental holograms in Reference [20] at the four selected time steps. They look similar but not quantitatively same, indicating the necessity of performing a viscous computation for this case.…”

“…The first case considered here is the subcritical head-on interaction case in Reference [20]. Our objective is to use the experimental data in Reference [20] to verify the significantly reduced numerical diffusion in the direct Euler simulation by combining the two-step grid redistribution method of Reference [19] and the improved spatially third-order accurate Euler solver of Reference [14].…”

“…Our objective is to use the experimental data in Reference [20] to verify the significantly reduced numerical diffusion in the direct Euler simulation by combining the two-step grid redistribution method of Reference [19] and the improved spatially third-order accurate Euler solver of Reference [14]. According to Reference [20], the freestream Mach number is 0.5, and the vortex has a non-dimensionalized strength of 0.283 and a core radius of 0.018 chords. This is an extremely tight vortex and imposes a very strict requirement on the local grid resolution in the vortex region.…”

“…The measured time histories of the surface pressure coefficient at three chordwise locations (2, 5, and 10% of the chord length) in Reference [20] are used to verify the reduced numerical diffusion contained in the direct numerical simulation by combining the two-step grid redistribution method of Reference [19] and the improved spatially third-order accurate Euler solver of Reference [14]. It is found in Figure 5 that compared with multiblock grid Navier-Stokes results in Reference [20] based on nearly 193 000 points, our adaptive Euler computation with only about 32 800 points gives much steeper slopes of the pressure and much larger peak values due to much less numerical diffusion inherent in the computation.…”