Divertless Supersonic Intakes (DSI) is an air intake that was designed for supersonic flight regime, so the plane doesn´t need to have any variable-geometry airintake, that´s why it is called DSI. In supersonic flight regime, it is hard for an airplane to turn, especially kulbit. In order to gain airflow to the engine, most fighters uses variable-geometry air intakes, or moving air intakes that we could found in F-22, or Su-27, or MiG-29, or any other fighters. Fighter such like F-35 doesn´t need any moving parts because it uses DSI. DSI automatically gain airflow to the engine in supersonic flight regime. I hope it helps, have a nice day
DSI stands for Divertless Supersonic Intakes, the only plane before FC-1 (JF-17) to have DSI is the JSF/F-35. The bumps seen at the intakes are litterally called Bumps. At high aircraft speeds through supersonic, the bumps work with forward-swept inlet cowls to redirect unwanted boundary layer airflow away from the inlets, essentially doing the job of heavier, more complex, and more costly approaches used by current fighters. It proved to save significant weight and It improves performances both when supersonic and subsonic. The DSI bump functions as a compression surface and creates a pressure distribution that prevents the majority of the boundary layer air from entering the inlet at speeds up to Mach 2. In essence, the DSI does away with complex and heavy mechanical systems.