Shipbucket

I just showed that video to my division (CA division or Combat Acoustics aka the SONAR division) and we all had a good laugh. Thanks for that.

NAS (Next-Generation Attack Submarine)
Specifications
Displacement:
Submerged: 6,400 t
Dimensions:
Length: 111 m
Beam: 11.4 m
Draft: 9.3 m
Electronics:
Combat Management System: AN/BYG-1
SONARS: AN/BQQ-10 SONAR Suite
AN/BQG-5A Wide Aperture Passive Flank Array
TB-29(A) Towed Array
Periscopes: 2 x AN/BVS-1 Photonic Masts
Radar: AN/BPS-16(V)4
Electronic Warfare: AN/BLQ-10

Weapons:
Torpedo tubes: 4 x 53 cm
Torpedoes: Mk 48 ADCAP
Missile Tubes: Variable
Missiles: Variable

Machinery:
Nuclear Plant: 1 x General Electric S9G PWR, 2 Turbo-Generators
Pump Jets: 4 x 7,000 hp (28,000 hp / 21 MW) Pump Jets

Structure: An evolution of the SSN-21 Program, the NAS design was selected to replace the aging 688 fleet of SSNs . The NAS sacrifices the top speed and weapons payload of the Seawolf class for improved stealth and flexibility in payload.

NAS has a reconfigurable mission bay (RMB) capable of carrying a variety of purpose built mission modules. These modules consist of various missile launch systems, mine laying, special forces and intelligence operations equipment. The major mission modules can be swapped out in a matter of weeks at specialized shore facilities and lesser alterations can be made by submarine tenders.

In addition to the RMB the NAS uses a distributed propulsion system (DPS) consisting of four (4) 7,000 hp turbo pump jets. In addition to SSN-21 level quieting already integrated into NAS systems, the pump jets reduce exploitable broadband and narrowband signatures even further. It is estimated that NAS can remain undetected by any sensor system currently employed.

why 4 pump jets exactly, as larger propellers are more efficient?
I also doubt how you can design an pumpjet powerplant without the intake, that intake is the most important part of your sub in both power and noise.

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

Im modeling the intakes and the whole system is quite complex its taking time. Propeller is more efficient than pumpjet?!? Please remind me of the shaft/blade configuration for Seawolf? Virginia? Astute? Trafalgar? Vanguard?

if an pumpjet is more efficient then an propeller depends on the speed it operates on and the relative size of the parts, but keep in mind that in an pumpjet there is an propellor. the diameter of that one was what I meant.
all these subs have 1 propellor. why have you 4? you make the diameter smaller (thus limiting the length inside the shaft before cavitation, and limiting the efficiency because with the diameter getting smaller, the relative rotation speed goes up and thus the efficiency down)

all these submarines have an pumpjet based off an specially shaped duct around the propellers, while your idea of am pumpjet seems to be completely different, judging your stern shape?

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

and that is? with just nice pictures without an actual concept behind it you don't tell me anything.
EDIT: ow just posting another 'nice pic' of something that doesn't work instead of answering my doubts -.- that is what you did. I'm out of here, I am wasting my time.

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

Good. I'm really glad to see you leave the thread because you never add anything of value. I'm not going to google every answer for you. Since you seem more concerned with critcizing peoples work and ideas, and not investigating facts, here you go:

http://www.freepatentsonline.com/6581537.html
http://www.navy.mil/navydata/cno/n87/us ... ystem.html
http://www.darpa.mil/default.aspx
http://www.accessscience.com/pages/new-and-noteworthy

Any constructive comments, I'll be happy to entertain. Thanks for your time.

wait, your propulsion is an set of centrifugal pumps connected to an water intake connected to an tube that leads to an waterjet exhaust?
yep, inefficient, noisy, and something I had not in what I said earlier, huge. that somebody patents the idea does not mean it is an idea that is actually better then what exists, you know? what you have now is not an pumpjet, it is thunderbirds.

and about never adding anything constructive: then I might be the only one of us who actually tries to make your designs realistic.

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

I get it. You read a text book and now you are an ASW expert, way more qualified than the two PhDs with more than 45 years of research experience. I guess its not unrealistic considering that you read the entire pdf in less than a minute.

Do me a favor, and worry about making your modeling look more realistic and less time about mine. Thanks.