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Figure 4:
UHCA: Surface pressure distribution and streamlines
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Turning the attention to three-dimensional testcases, an Ultra-High Capacity
Aircraft (UHCA) wing-body configuration, Fig. 4, is computed at ,
and
. This case is of particular interest since it
represents a combination of high Mach numbers and a comparatively high
angle-of-attack for transonic flows, yielding a shock-induced separation over
large portions of the wing, see Fig. 5. A grid generated by Airbus
Germany of 52 equal-sized blocks with
mesh nodes and
38,642 surface points, totalling to approximately 2.4 million points, is
employed. A
is guaranteed over most of the wing surface. The transition location is prescribed according to given data. The computations are performed with FLOWer, LLR and LEA - are compared to the baseline Wilcox model.
The pressure distribution in selected wing sections are given in Fig.
6. While the pressure side including the rear loading is captured
very well by all models, a clear improvement in the prediction of the shock
location on the suction side from Wilcox over LEA to LLR - is
visible in the mid-span section. However, in the most outboard section,
the shock appears to be somewhat smeared out, probably owing to an insufficient
grid resolution in this region. Thus, it is not possible to make a clear judgement whether LLR or LEA - yields a superior prediction here. Nonetheless, the enhanced predictive accuracy with respect to the Wilcox model is evident.
Figure 5:
UHCA: Surface pressure distribution and streamlines
on wing upper surface, LLR -
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Figure 6:
UHCA: Pressure distribution in selected wing sections
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Next: Wing-Body-Pylon-Nacelle Configuration
Up: Cruise-Flight Conditions
Previous: RAE 2822 Aerofoil
Martin Franke
2003-10-22