There are 3 sea wolf-class, 6 Virginia-class and about 40 Los Angeles-class attack nuclear submarines.

Among them, the earlier Ohio class and Los Angeles class are both propeller propulsion:

-Ohio class

The newer Sea Wolf Class and Virginia Class are pump jet propulsion;

-General Zhang once said that the water pump jet would be entangled with kelp and was scolded by the audience.

The so-called pump-jet system simply means that water is sucked from the front, and then pressurized and ejected by the propeller to generate thrust and push the submarine forward. Its complexity lies in that the submarine pump jet propeller is a combined propulsion device consisting of annular duct, stator and rotor. The cross section of the annular duct is wing-shaped, covering the rotor and stator, and it is the control surface of the internal and external flow fields of the pump jet propeller. If sound absorption and vibration reduction materials are used, the noise generated by the rotor and the internal flow passage can be shielded. In order to delay the cavitation of rotor blades and reduce the noise of the rotor, deceleration ducts are usually used to reduce the flow velocity of the rotor. Stators are a group of fixed blades at a certain angle to the incoming flow, which make the rotor flow pre-swirl or absorb the rotational energy of the rotor wake, and are also used to fix the duct; The rotor is a rotating impeller similar to a propeller, which generates thrust through the interaction with the water flow and pushes the submarine to reach the required speed.