Seawolf pump jet

[James Wittaker]

Does anyone know what the pump jet propellers of the Seawolf class submarines looked like? There are two different drawings, one showing a longer propeller cowl and the other a shorter one. The various drawings seem to be uniform regarding the number of stator and rotor blades.

[CC Clarke]

Over a period of about three months, I built a highly detailed 3D model of the Jimmy Carter using official Navy documents and reference photos in a former job. The pump jet propulsor is still classified and anything you see online is speculation. Make it whatever way looks best to you.

CC

[He Who Shall Not Be Named]

Over a period of about three months, I built a highly detailed 3D model of the Jimmy Carter using official Navy documents and reference photos in a former job. The pump jet propulsor is still classified and anything you see online is speculation. Make it whatever way looks best to you.

CC

Here's some speculation for you. 1/48, 1/72, and 1/144 PJ's we produced for the market. Also, a commissioned 1/96 SEAWOLF model on display at the Nautilus Museum:
































































David

[Woogey]

Well holy hell DAVID! Those things are works of art. How much would something like that cost individually for sale 1/72 scale boat?

-Preston

[He Who Shall Not Be Named]

Well holy hell DAVID! Those things are works of art. How much would something like that cost individually for sale 1/72 scale boat?

-Preston

No longer available. I'm retired. I have a bucket-list (and previously made commitments to fulfill) awaiting my remaining productive years.

David

[Sam Victory]

Here is a blurry photo of the Connecticut, with the pump-jet thrusters on the stern for reference.

V

[Sam Victory]

Connecticut:


Virginia:



V

[Sam Victory]

I have previously read some references on the design of submarine PJs. According to the relative position of the stator and rotor, the pump jet propeller is further divided into two types of forward and backward rotation, the stator before the rotor is called “ rear rotation” and the stator after the rotor is called “forward rotation”. The larger the chord length ratio of the rotor, the more beneficial for delaying the generation of air bubbles, but the disc ratio increases, the propulsion efficiency decreases (the same situation as the propeller); and the larger the gap between the stator and the rotor, the less noise, because the smaller gap tends to make the water flow between the stator and rotor interfere with each other, producing high-frequency discrete noise. Long-term experiments have confirmed that the rotor and stator number of prime numbers when the noise is smaller, so the number of rotor and stator blades is best 7, 9, 11, 13 and other numbers, and the stator blades must be lower than the number of rotor; In addition, the tail flow control ability of the backward rotor design is better, the structure is lighter, but the cavitation effect is larger, the forward rotor characteristics are completely opposite. Most of the submarine pump jet use the better performance of the backward rotor with better silent performance of the deceleration tube design as a compromise, such as the British Trafalgar class, Vanguard class, etc., while the Sea Wolf class uses the silent performance of the forward rotor （stator with a certain torsion angle at the rear）design. So I guess the PJ of the Seawolf class submarine is like this: the front of the deflector tube is supported by 4 blades to hold the deflector tube. In the middle is a 9-bladed rotor and at the end is a 7-bladed stator, part of the description can be found in the picture below.

V