Classification methods of hypersonic inlet start/unstart based on rough set

Inlet start/unstart detection is one of the most important issues of hypersonic inlet and is also the foundation of inlet protection control. To solve this problem, the 2-D inner steady flow of hypersonic inlet at different flow conditions and back pressures was numerically simulated. The sensor location reduction to the inlet by using rough set algorithm was presented. The judgment criterion of hypersonic inlet start/unstart was given and the inner physical mechanism was analyzed. The judgment criterion was validated by the else simulation data, the result proves the validity.