Indian nuclear submarines

[MonaLazy]

190 MW for 6000 tonne SSN seems a bit OP

Alfa-class submarine - Wikipedia

en.wikipedia.org

The Alfa class, Soviet designation Project 705 Lira (Russian: Лира, meaning "Lyre", NATO reporting name Alfa), was a class of nuclear-powered attack submarines in service with the Soviet Navy and later with the Russian Navy. They were the fastest military submarines ever built, with only the prototype submarine K-222 (NATO Reporting Name Papa-class) exceeding them in submerged speed.

A hunter killer submarine, it had 155MWt pushing 3200 submerged tons upto a speed of 41 knots. Can't do that with 83MWt of Arihant class.

 

[Lonewolf]

Alfa-class submarine - Wikipedia

en.wikipedia.org

The Alfa class, Soviet designation Project 705 Lira (Russian: Лира, meaning "Lyre", NATO reporting name Alfa), was a class of nuclear-powered attack submarines in service with the Soviet Navy and later with the Russian Navy. They were the fastest military submarines ever built, with only the prototype submarine K-222 (NATO Reporting Name Papa-class) exceeding them in submerged speed.

A hunter killer submarine, it had 155MWt pushing 3200 submerged tons upto a speed of 41 knots. Can't do that with 83MWt of Arihant class.

Yup also the reactor need to be silent as hell

 

[gearedcombustor]

The 190 MWt for SSN is just an assumption/wishlist by media and wikipedia editors. No basis for that assumption. We don't know what CLWR-B2's power rating actually will be. Navy and BARC never talked about it.


We know that Navy published an EoI for 35 MW electric drive motor for pumpjet propulsion at max speed of 25 knots. At 35 MW shaft power, assuming the standard 20% lowest end efficiency for naval reactors, will require 175 MWt to drive the shaft alone. Sensors and onboard power required will be extra but we don't know under what conditions it is supposed to operate at 35 MW. ( Don't compare with civilian power reactors with efficiency near 30% - naval reactors only have efficiency around 20 to 23 %)

Operating power in the 160 to 170 MWt range is probably what they will target with surge power of 190 MWt if they go for a clean sheet non-licensed low cost design. Akula has operating at 190 MWt with surge limit unknown.

Also if they tested a 350 kW, probably implies a 0.01 scale of the target 35 MW

If they really build a 35 MW PMSM motor, it will be the largest naval PMSM in the world. The current highest is the nearly 20 MW motor of unknown type (probably PMSM only) in the Barracuda/Suffren the sole design with Nuclear Electric Propulsion instead of direct steam turbine drive. Americans and Russians don't use NEP yet.

That motor will need a lot of phases and switching/IGBT gear and will probably the most fun to design from an electrical engineering perspective.

I don't know how feasible this is or how reliable & heavy such a design will be. It's probably less technically risky to go with steam propulsion but we Indians do not have expertise in designing such high power compact gearboxes without external help.

 

[shuvo@y2k10]

If a 190 MW reactor is sucessfully build, can it power our future aircraft carrier?

 

[Haldilal]

If a 190 MW reactor is sucessfully build, can it power our future aircraft carrier?

Ya'll Nibbiars will require atlest 500 to 900 MW power. The Gerald R ford is powered by two A1B 700 MW reactors.

 

[gearedcombustor]

Ya'll Nibbiars will require atlest 500 to 900 MW power. The Gerald R ford is powered by two A1B 700 MW reactors.

Can be done with any current reactor design. The only factor will be cost efficiency. Manufacturing and maintenance cost efficiency will probably call for 3x200 MWt or 2x300 MWt. 8x83 MWt will be very cost inefficient.

NEP is not necessary as you can combine the steam generator output channels of all reactors and drive 2 main steam turbines with the current style of gearbox. NEP will be a added benefit.

 

[MonaLazy]

If a 190 MW reactor is sucessfully build, can it power our future aircraft carrier?

Once the tech is mature to go into a cramped submarine where stealth and space are over riding concerns- it is relatively easy to create ACC nuclear reactor by scaling up (core size, coolant and fuel) and going easy on the noise suppression.

ACC is never operating in quiet mode - infact it is the epitome of quite visually in your face naval strength and space is not a problem. Submarine nuclear reactor is an order of magnitude harder to crack.

 

[gearedcombustor]

Another one from my comment on other forun to summarise:


This is probably the first stage of the PMSM work for SSK's and SSN's.

We have seen an EoI for a 5 MW drive motor for an SSK retrofit - likely Kilo class but don't know whether BHEL will go with PMSM or stick to the original DC type in the Kilo.

5 MW is the next step for BHEL and can probably be delivered very quickly.

An IN EoI for 35 MW drive motor for pumpjet propulsion also exists. A 35 MW PMSM will be challenging to design - the technical risk will depend on achieving the compact design. They should probably have a backup plan sticking to the steam propulsion instead of attempting NEP/IEP for this.

The only similarly sized motor design is the 20 MW motor in the Barracuda/Suffren. I am not sure if it is PMSM or DC. Can't find any info from ECA-Jeumont or DCNS. The Siemens & Jeumont designs go to 4 MW max and the Japanese SMC-8 is 8 MW.

Running to the French will be of little help.

The main components of NEP are Reactor, Steam Generator, Turbine Generator, Drive Motor and Prop.

Reactor is probably doable without help of French. Steam Generator and Turbine Generator are trivial tech for BHEL and won't need any help whatsoever. Prop is a different beast and not necessary to be discussed right now.

For a 35 MW drive motor, French won't have any off the shelf design to share and will ask for 3 to 5 years to design with a huge usurius bill for ToT. Instead of paying that it's probably fine in not going with NEP.

Very optimistic take: (take with grain of salt) Spending the small time without the bill on the plan BHEL has now should be fine. Electric motor design is predictable and well understood and won't likely throw surprises. If there are feasibility issues they will know in the design process itself.

 

[MonaLazy]

Tsirkon hypersonic missile first time test-fired from Northern Fleet “Severodvinsk” nuclear submarine against a target in the Barents Sea

Can IN get here in 1 or 2 decades? A hypersonic missile fired off of a submarine that does not need refuelling over its entire service life!

 

[THESIS THORON]

Tsirkon hypersonic missile first time test-fired from Northern Fleet “Severodvinsk” nuclear submarine against a target in the Barents Sea

Can IN get here in 1 or 2 decades? A hypersonic missile fired off of a submarine that does not need refuelling over its entire service life!

IMO 1 DECADE

 

[THESIS THORON]

we have leased akula class or improved akula class ??

this will tell wether our subs will be quiter than chinkis upcoming type 095 subs.

 

[MonaLazy]

we have leased akula class or improved akula class ??

Improved Akula- Project 971I. Chakra-2 was Nerpa (K-152) which is an improved Akula I

Project 971 and 971I (Improved Akula I)[edit]
The six Akulas of this class are all thought to be in service. They are quieter than the original Akulas. The MGK-500 sonar is upgraded to MGK-501 Skat-MS. Sources also disagree as to whether construction of this class has been suspended, or if there are a further two units planned.

Improved Akula I Hulls: K-328 Leopard, K-461 Volk, K-154 Tigr, K-419 Kuzbass, K-295 Samara and K-152 Nerpa. These submarines are much quieter than early Akula-class submarines and all have the SOKS hydrodynamic sensors except Leopard.[14] The Akula I Improved submarines have six 533 mm decoy launching tubes, as do subsequent submarines. They have a different arrangement of limber holes on the outer hull than Akula Is. Submarines Nerpa and Iribis (not completed) have a different rescue chamber in the sail,[citation needed] which can be distinguished by the large dome on the top surface.

Russian submarine Nerpa (K-152) - Wikipedia

en.wikipedia.org

Akula-class submarine - Wikipedia

en.wikipedia.org

 

[Gessler]

we have leased akula class or improved akula class ??

this will tell wether our subs will be quiter than chinkis upcoming type 095 subs.

I'm not entirely sure if this graphic references the 971I or the U or M.

The U & M are the really quiet ones.

That said, even if we fully replicate the Akula's acoustics-mitigation techniques (any version, even the regular 971 is pretty quiet), how silent our SSN will turn to be, will be dependent on several other factors. For example, its highly likely our example will have, at the very least, a pump-jet propulsor....which no Akula has.

That should serve to address cavitation even at relatively high speeds.

If the Electric Drive becomes a reality, the Indian SSN might just become the quietest non-Western nuclear submarine in the world.

 

[THESIS THORON]

I'm not entirely sure if this graphic references the 971I or the U or M.

The U & M are the really quiet ones.

That said, even if we fully replicate the Akula's acoustics-mitigation techniques (any version, even the regular 971 is pretty quiet), how silent our SSN will turn to be, will be dependent on several other factors. For example, its highly likely our example will have, at the very least, a pump-jet propulsor....which no Akula has.

That should serve to address cavitation even at relatively high speeds.

If the Electric Drive becomes a reality, the Indian SSN might just become the quietest non-Western nuclear submarine in the world.

so are we researching on nep or will get tot from france ??

 

[Gessler]

so are we researching on nep or will get tot from france ??

The information available so far indicates we are doing R&D on it. How far along we are toward a workable solution, no idea.

Whether the French NEP will be transferred or not will depend on these things:

• Whether such offer is actually on table or not. Just because AUKUS happened doesn't automatically mean everything is on table.
• Whether their existing model (20MW), or some version that's within scalable range of that base design, will be sufficient for our needs or not.
• Whether our SSN and/or SSBN designs are at a stage where its reasonably possible to make critical equipment changes. If we are past the point of design freeze on either model, then it would be a far more complicated route to take (incorporating new kit).

 

[THESIS THORON]

so improved akula class in this pic seems to be project 971U (AKULA II)


Project 971U (Akula II)
K-157 Vepr is the only completed Akula II (see the table below).[15] The Akula II is 3 metres (9.8 ft) longer and displaces about 700 tons (submerged displacement) more than the Akula I. The added space was used for additional quieting measures. The MGK-501 Skat sonar system on Akula I is replaced by a new MGK-540 Skat-3 sonar system.[16] K-157 Vepr became the first Russian submarine that was quieter than the latest U.S. attack submarines of that time, which was the improved Los Angeles class (SSN 751 and later).[17] Two of these submarines were used to build the Borei-class SSBNs.


NOTE- SOURCE WIKI

project 688 is LOS ANGELES and 688i is IMPROVED LOS ANDGELES

(CHAKRA II) NERPA was project 971i

 

[gutenmorgen]

so improved akula class in this pic seems to be project 971U (AKULA II)


Project 971U (Akula II)
K-157 Vepr is the only completed Akula II (see the table below).[15] The Akula II is 3 metres (9.8 ft) longer and displaces about 700 tons (submerged displacement) more than the Akula I. The added space was used for additional quieting measures. The MGK-501 Skat sonar system on Akula I is replaced by a new MGK-540 Skat-3 sonar system.[16] K-157 Vepr became the first Russian submarine that was quieter than the latest U.S. attack submarines of that time, which was the improved Los Angeles class (SSN 751 and later).[17] Two of these submarines were used to build the Borei-class SSBNs.


NOTE- SOURCE WIKI

project 688 is LOS ANGELES and 688i is IMPROVED LOS ANDGELES

(CHAKRA II) NERPA was project 971i

True, I think. According to wiki sources, 971U was the first submarine that was quiter than the then latest US submarine, which was improved LA class. Up until this point, the US submarines were always quiter than their russian/soviet counterparts.
That being said, 971I should be somewhere between Akula and Improved Akula on the graph. Maybe on the same level as the original los angeles class.

 

[Indx TechStyle]

190 MW for 6000 tonne SSN seems a bit OP

Inaccurate reporting.
190 MW reactor is being built for S5 class submarines.

 

[THESIS THORON]

Inaccurate reporting.
190 MW reactor is being built for S5 class submarines.

so are they building another one for ssn??

bec 83MW will be insufficient

 

[Indx TechStyle]

so are they building another one for ssn??

bec 83MW will be insufficient

Yes likely.
But the reactor which is in officially public domain; CLWR-B2 (190 MW) is for S5 class SSBN. We don't know about others.