Analysis of PSP Results Obtained for the VFE-2 65° Delta Wing Configuration at Sub- and Transonic Speeds

What was learned from the new VFE-2 experiments

“…Unfortunately within VFE-2 not all details of the onset of vortical flow in the front part of the configuration could be investigated experimentally because of geometric constraints of the PIV setup in the wind tunnel, but due to the encouraging agreement between the experimental and the calculated results, further study of these details can be guided with analysis of numerical solutions. A series of pressure distributions for M = 0.4 and R mac = 3 million and for various angles of attack from the PSP measurements 15,19 at DLR Goettingen is shown in Fig. 9.…”

Numerical simulation of the peculiar subsonic flow-field about the VFE-2 delta wing with rounded leading edge

“…At the end of these validation calculations first results of new VFE-2 measurements were available [11]. The PSP measurements at DLR have shown very clearly the footprint of a second primary vortex for the round leading edge test case [14]. The origin of this second primary vortex was not clear from the PSP results, but in [1] there is already given a first numerical visualization of this second vortex by Chiba and Obayashi. So at EADS the simulation of this second primary vortex was also considered as a special assessment of the quality of the CFD tools, and some additional work towards the simulation of this peculiar flow field was done.…”

What was Learned from the New VFE-2 Experiments?

“…A series of pressure distributions for M = 0.4 and R mac = 3 million and for various angles of attack from the PSP measurements 15,19 at DLR Goettingen is shown in Fig. 9.…”

“…It starts earlier than the outer suction peak and the shape of its initial pressure distributions resembled that of a separation bubble related to the transition from laminar to turbulent flow 13 . After the formation of the primary vortex the inner suction peak reduces more and more in the downstream direction 14,15 . On the right-hand side of the colored central plot in Fig.…”