My chart looks a little different than yours Badboy. Is there anything wrong with expressing the curves this way?
That depends why you have drawn the chart. As Baumer points out, if you just want it to look good, up might be better than down from an aesthetic perspective. But joking aside, we do need to be clear about our reasons for drawing any chart, and what information we want to extract from it.
The chart I've drawn is intended to show the relationship between altitude and speed when an aircraft dives or climbs. There are some well known characteristics associated with those maneuvers that should be reflected in the chart. For example, we know that when an aircraft dives it gets faster, and that when it zoom climbs it gets slower again. You can see that this relationship holds true in the charts I posted. For example, in the first chart, if the aircraft at A at 8000ft & 250mph were to descend to 6000ft it can be seen from the chart that its speed would increase by 100mph, providing the aircraft didn't lose or gain energy during the process.
The assumption we are making here is that the energy state of the aircraft remains constant during the climbs and dives, that being so we need to draw lines on the chart that represents that constant energy state, that is lines of constant Es. The lines on my chart are lines of constant Es. They have the feature that if you lose altitude, you gain speed so that the Es stay the same. Similarly, if you gain altitude you lose speed for the same reason. That's a proper reflection of what happens in flight and it is the way these diagrams are drawn in military sources.
You can find another description of this beginning on page 392 of Shaw, and a diagram similar to mine on p395 of Shaw.
Sorry, but I can't seem to see what your chart is telling me.
Badboy
