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The adjustment process can be regarded as a process of flow rate change; as the flow rate decreases, the axial velocity of the airflow diminishes while the impact angle increases. At this point, the airflow strikes the working surface of the blade, causing separation to occur on the non-working surface, which can then expand easily. When the flow rate is low enough, the detachment zone expands significantly. Experiments show that the movement speed of the detached mass within the working wheel relative to the blade is less than the circumferential speed of the rotor; therefore, when viewed in an absolute coordinate system, the detached mass moves in the direction of rotation of the rotor at a certain rotational speed, which is what is known as \"rotational detachment\". When the flow rate drops to a critical value, large areas of detached flow regions emerge, occupying a significant portion of the channel; this leads to a sudden and significant decline in performance, a phenomenon known as \"sudden stall.\" When severe rotational detachment occurs and sudden stall is triggered, although the rotating wheel does work on the gas, it is unable to increase the gas pressure, resulting in a drop in the compressor outlet pressure. Since the compressor is always connected to the piping system, if the capacity of this piping system is large, its response is not immediate; as a result, the pressure in the piping system does not drop right away. This leads to backflow, with the pressure in the piping system being higher than the pressure at the compressor’s outlet. Backflow stops once the pressure in the piping system drops to the level of the compressor’s outlet pressure, after which the flow moves in the correct direction again due to the action of the blades, and the compressor begins to supply air. However, as the pressure continues to rise back to its original level during this period of waiting, obstacles arise in the compressor’s exhaust flow, causing the gas to flow in reverse. This cycle repeats itself, resulting in periodic fluctuations in airflow – this phenomenon is known as \"surge\". The consequences of surging are extremely severe; it causes the compressor rotor and stator to be subjected to alternating stresses, leading to fractures ； This causes abnormal pressure between stages, leading to severe vibrations and resulting in damage to the seals and thrust bearings ； It causes serious accidents by bringing moving components into contact with stationary components.