View attachment 685603
Research from 1970s to 1990s
You can see that it was round inlet in 1990, however, it became a variable geometry inlet in 1992.
So,what happen to J-10's inlet, which finally become a variable geometry inlet.
The answer is the change of engine.
Although it has been confirmed that the J-10 uses turbofan engine, due to its long development cycle, it can't keep up with the development cycle of the aircraft, so liming Company received the task of modifying WP-15 engine as a temporary engine.
So the J-10 was originally designed based on FWP-15(More precisely, FWP-15A) engine.Because of its high-altitude and high-speed performance, it only needs round inlet to meet the requirements.
However, its installation, size and characteristics are quite different from FWS-10.
Finally, As the installation position of AL-31FN and FWS-10 is the same, the size profile does not exceed FWS-10, the center of gravity is more forward than FWS-10, the weight is almost the same, and the performance change law is similar, etc, the decision to use AL-31FN was issued in 1992.
The research of FWP-15A for J-10 was stopped.
As the high-speed characteristic of AL-31FN is not as good as FWP-15, 611 had to modify the intake design to meet its original design requirements.So we can see that in 1992, the design of J-10's inlet has become a variable geometry inlet.
