00X/004 future nuclear CATOBAR carrier thread

[taxiya]

If I look at the graphic, it looks like the power requirements for a Type-052D sized ddestroyer:

38MW for full speed propulsion.
4MWe hotel load
10MWe combat load

And during combat, energy supplied to propulsion is cut in half.

The definition of "efficiency gain" looks like it comes from the 10MWe of combat load 10/52=20%. That means total installed power could be 20% less for a Type-052D.

But lets say the combat load doubles to 20MW. It's now 20/62 which is a 32% reduction in total installed power.

The paper is about a 4000t frigate without the kind of radar on a 052D. So the combat load should be much higher than 10MWe for a 052D. But the load budget should be in similar percentages.

---

But for a Nimitz, the calculation is more like a maximum of 10MW of combat load on a total loading of about 250MW. So that would only be a 4% reduction in total installed power required.

Nimitz does not have full sized AESA radars that Ford and 004 have, who are in the same range as 052D or even 055. So 20MWe is more closer than 10MWe. Worth to point out that the discussion started as "why Ford's 104MWe seems excessive", Nimitz shouldn't be brought in as it has very low electricity demand.

Also it is stated by USN official that the installed electricity capacity of Ford class is 104MWe. What is 250MW from, electric or thermal? If you are talking about thermal power, 104/0.3=347MWth. Since Ford is not IEPS, there is 1053MW thermal (316MW shat) dedicated for propulsion.

Regardless how you see it, 20MWe is 20% of 104MWe of installed electric power capacity, not 4% of something.

---
So the efficiency gain is highly dependent on what the combat load is.

Yes, it is true in principle, but doesn't change anything as stated above.

 

[RedGreekRevolt]

The paper is about a 4000t frigate without the kind of radar on a 052D. So the combat load should be much higher than 10MWe for a 052D. But the load budget should be in similar percentages.


Nimitz does not have full sized AESA radars that Ford and 004 have, who are in the same range as 052D or even 055. So 20MWe is more closer than 10MWe. Worth to point out that the discussion started as "why Ford's 104MWe seems excessive", Nimitz shouldn't be brought in as it has very low electricity demand.

Also it is stated by USN official that the installed electricity capacity of Ford class is 104MWe. What is 250MW from, electric or thermal? If you are talking about thermal power, 104/0.3=347MWth. Since Ford is not IEPS, there is 1053MW thermal (316MW shat) dedicated for propulsion.

Regardless how you see it, 20MWe is 20% of 104MWe of installed electric power capacity, not 4% of something.


Yes, it is true in principle, but doesn't change anything as stated above.

Please, Log in or Register to view URLs content!

At least according to wikipedia each of the two Ford reactors has 700 MW thermal and 125 MW electric.

 

[taxiya]

Please, Log in or Register to view URLs content!

At least according to wikipedia each of the two Ford reactors has 700 MW thermal and 125 MW electric.

Both figures are deduced from the inprovement figure of percentage (which is official) over supposed Nimitz figures which are NOT official statements. So wikipedia is telling nothing but people's guesses. The only official figure relatively reliable is USN official's statement of 104MW electricity capacity of Ford class.

A general rule is to read the quoated source of any figures and check what kind of source that is, wikipedia is just a gathering point of information including plain rumors. Among engineers we call something "shit in, shit out", a solid mathematic formular will only produce rubish if its fed with rubish. There are just too little reliable inputs, but people rush to make too many conclusions based on wrongly applied mathematic formulars.

 

[AndrewS]

The paper is about a 4000t frigate without the kind of radar on a 052D. So the combat load should be much higher than 10MWe for a 052D. But the load budget should be in similar percentages.

That doesn't sound right.

The 4000tonne Type-054A has 20MW for propulsion
The 6000tonne Type-054B has 29MW for propulsion

38MW for propulsion is almost the 40MW required for the 8000 tonne Type-045 Destroyer.

I don't think we can generalise that IEPS results in a roughly 20% decrease in total output required for Frigates or Destroyers.

The ratio can really change, depending on the propulsion requirement for a ship plus combat electricity load

Nimitz does not have full sized AESA radars that Ford and 004 have, who are in the same range as 052D or even 055. So 20MWe is more closer than 10MWe. Worth to point out that the discussion started as "why Ford's 104MWe seems excessive", Nimitz shouldn't be brought in as it has very low electricity demand.

Also it is stated by USN official that the installed electricity capacity of Ford class is 104MWe. What is 250MW from, electric or thermal? If you are talking about thermal power, 104/0.3=347MWth. Since Ford is not IEPS, there is 1053MW thermal (316MW shat) dedicated for propulsion.

The 250MW comes from 200MW (propulsion) and roughly 50MWe (given that you want some slack from the total available of 64MWe)
And a presumed loading of 10MWe for combat. Hence roughly 10MW out of a total of 260MW

Regardless how you see it, 20MWe is 20% of 104MWe of installed electric power capacity, not 4% of something.


Yes, it is true in principle, but doesn't change anything as stated above.

 

[daifo]

Type 76 had an additional 2 close defense weapon over Type 75. I don't think it should be controversal to think that PLAN will up the number on their other capital ships. Based on the ground variant a significant part of it is above the hull and not taking much inside space. The first batch of missles are already in the hq-10 launchers and its possible that ammo for the ciws gun are also stored in the gun compartment.

 

[taxiya]

That doesn't sound right.

The 4000tonne Type-054A has 20MW for propulsion
The 6000tonne Type-054B has 29MW for propulsion

38MW for propulsion is almost the 40MW required for the 8000 tonne Type-045 Destroyer.

The 4000t frigate is a paper by PLAN researcher, I have shown it in this forum. I don't know what does not sound right to you. Or you know better than naval engineers?

I don't think we can generalise that IEPS results in a roughly 20% decrease in total output required for Frigates or Destroyers.

Fair, then you should stop all your calculations based on unrealiable figures and quastionable calculations.

The ratio can really change, depending on the propulsion requirement for a ship plus combat electricity load





The 250MW comes from 200MW (propulsion) and roughly 50MWe (given that you want some slack from the total available of 64MWe)
And a presumed loading of 10MWe for combat. Hence roughly 10MW out of a total of 260MW

Where did you get this figure 250MW? Research paper? USN official? If you can't get this source right, why do you even bother to continue calculating? This is what we engineers call "shit in, shit out".

You are getting more and more ridiculous, if you think you have a better idea than a naval engineer, I will stop the debate right here and now with you.

 

[AndrewS]

The 4000t frigate is a paper by PLAN researcher, I have shown it in this forum. I don't know what does not sound right to you. Or you know better than naval engineers?

It's a paper on a hypothetical 4000 tonne Frigate.
I'm using propulsion figures based on what we see in real life with Frigates and Destroyers.
Real-life beats a hypothetical paper.

Fair, then you should stop all your calculations based on unrealiable figures and quastionable calculations.

Where did you get this figure 250MW? Research paper? USN official? If you can't get this source right, why do you even bother to continue calculating? This is what we engineers call "shit in, shit out".

You are getting more and more ridiculous, if you think you have a better idea than a naval engineer, I will stop the debate right here and now with you.

It comes from 200MW required for the driveshafts on a Nimitz carrier + say ~50MWe used out of 64MWe available.

Yes, these are approximate figures. But whether the denominator is a total 250MW or 264MW, doesn't change the conclusion

 

[Chaos314159]

What are you people arguing about actually?

 

[HailingTX20]

Latest image with not much changed:

 

[Syrida2887]

Have we seen the picture from this side?