But why do they want to improve the aerodynamic? It may increase the top speed by some degree, but definitely not going to improve it fundamentally. So the primary goal is still to improve the fuel economy. They are definitely not doing it for saving money, so it is mainly for increasing range of the jet, which is the same objective of increasing fuel capacity.
To sum up, they added the hump to increase the range, at the cost of physical rearward visibility.
Would you please NOT argue against the designers of FC-31 about what they think? It is ridiculous for a person to tell other people's mind. Here is the conclusion chapter of the research paper of the FC-31 modification.
Translation:
- Using simple design method of flap, combined with wing curvature optimization, the design can attain lift requirement under the restraint of stealth fighter.
- By optimizing the position of the canopy and the shock wave compression/expansion flows of the aft fuselage and optimizing air inlet bleeding vector (need better translation), we can attain 10% increase of drag reduction without sacrificing total fuselage volume.
- By utilizing the curvature optimization between the under side of fuselage and the arresting hook area, we can reduce the negative lift of horizontal stabilizers.
Only bold texts in point 2 are related to the canopy change and none of the 3 conclusions are related to "increased fule capacity" as a purpose or a desired result. It may give some extra room, but that certainly was not why the designers did the changes.
Another point is that, by reducing at least 10% drag (more than that when all 3 are put together), the range is certainly increased by a very large margin, there is even less desire to add extra fuel tank behind the canopy. Remember adding tank is nothing simple, since fuel are constantly consumed, it's distribution changes which changes the center of mass which need to be carefully regulated throughout the flight time of the aircraft, it is no easier than any other major systems in the aircraft.
There is just too much "I see, so I think" BS by the internet "experts" such as this TYLER ROGOWAY. I wouldn't even bother to read the article when I saw that he is the author.