Figure 6.2(b) shows the same test problem as before but with the superbee method. The discontinuity stays considerably sharper.On the other hand, we see a tendency of the smoothhump to become steeper and squared off. This is sometimes a problem with superbee – by choosing the larger of the neighboring slopes it tends to steepen smooth transitions near inflection points.
With these assumptions, the compressible energy equation is greatly simplified so that the resulting low-Machnumber equations are represented in tensorial notations as follows: