09III/09IV (093/094) Nuclear Submarine Thread

schenkus

Junior Member
Registered Member
But I agree, speculating about nuclear submarine acoustic stealth levels and especially trying to compare them on some kind of detailed basis is very difficult to do. Nuclear submarines are among the most closely guarded secrets of military forces which have them, for good reason.

I think a good hint about chinese nuclear submarines not yet catching up is that the US navy seems to be happy with their current submarines. Once the performance of chinese nuclear submarines gets close enough that the US navy gets worried I would expect to hear loud demands for extra budgets to build a next generation of SSNs and SSBNs.
 

Iron Man

Major
Registered Member
I think a good hint about chinese nuclear submarines not yet catching up is that the US navy seems to be happy with their current submarines. Once the performance of chinese nuclear submarines gets close enough that the US navy gets worried I would expect to hear loud demands for extra budgets to build a next generation of SSNs and SSBNs.
This is not really a good measure of Chinese sub tech levels. One is that the Type 095 isn't even in the water yet. Second, if the 095 is at 688i level or something in between 688i and Seawolf/Virginia, the USN may still be satisfied that they have an edge in sub tech. Third, US is already planning to build a new generation of SSBN (Columbia class) and Virginia is already getting updated by blocks, so nothing is standing still here.
 

Hendrik_2000

Lieutenant General
I doubt quieting technology in new/updated PLAN nuclear submarines comes close to Western SSN/SSBNs. Should Pentagon officials release an updated version of their 2009 submarine quietness chart, and if that shows dramatic improvement in Chinese nuclear submarine quieting technology, then I'll revise my outlook.

That pentagon updated quietness char is nothing but guesstimate because they predict the noise level of type 95 when the said sub is not even built

How the hell can they tell NOISE for a sub that is not even built . That chart has been around for a long time and they did the same thing with type 93
IT IS NOTHING BUT VODOO SCIENCE!

We know the characteristic of latest iteration of type 93B as close to Ohio class submarine natural circulation reactor, 9 blade propeller, engine on the raft ,anaechoic tile, tear drop and symmetrical shape body with ellipse front

Type should be better that is why they decide to mass produce them! following tradition in PLAN to mass produce platform once they satisfied it reached world class standard We see this over the year
 
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schenkus

Junior Member
Registered Member
This is not really a good measure of Chinese sub tech levels. One is that the Type 095 isn't even in the water yet. Second, if the 095 is at 688i level or something in between 688i and Seawolf/Virginia, the USN may still be satisfied that they have an edge in sub tech. Third, US is already planning to build a new generation of SSBN (Columbia class) and Virginia is already getting updated by blocks, so nothing is standing still here.

I agree that "the US navy is not worried yet" doesn't really help us understand how far China is behind - but I think it indicates that the US navy is confident China will stay behind for some years to come.
 

azesus

Junior Member
Registered Member
I don't get it why some people seems to get their mind stuck on China needs to follow US's tech R&D footsteps just because China was poor back then so they couldn't do any research that does not mean they could not skip some ladder on the tech tree. Just like starting with 052C have AESA while the Burke IIA still use PESA it's not hard to imagine 095 would have silmar analogous advantage compared to the Virginia. This reminds me during the 80's US can't believe that Japan's automotive industry can out done the US but look at the situation now. How did ONI get their research from something that didn't even exist, like they have a Time Machine or they were busy doing their research with Fat Leonard's fun fun girls told them how loud the 095 was with them last night bring them the Big O stands for on the "O"NI chart?
 

Hendrik_2000

Lieutenant General
Soft material with high heat and pressure tolerance

I got it yup that should do it . You see even though they isolate machinery vibration by putting it on the raft. Therefore isolate it from the hull. The pipe is connected to the pump now the pipe become the source of vibration.

To alleviate the problem you can shorten the span(the pipe length between 2 support)
But doing that only exacerbate the thermal stresses due to temperature
It is difficult because you have to satisfy 2 diametrically opposite requirements

Now if they can find material soft enough but yet strong enough to withstand high temperature and high pressure than they basically solve the problem of pipe vibration
If this new is true it mark REAL BREAKTHROUGH!

Pipe vibration is bad because it connected to pipe support which in turn connected to the structure and hull And from hull to water.

Yup a lot of people underestimate Chinese submarine. China has shown to make quantum leap in different platforms in air force, navy, ground force equipment
They say they need proof . But china sofar has won 2 diesel submarine contract competing against the best in the world. If that is not proof I don't know what.
NOBODY BUY NOISY SUBMARINE!
 
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vincent

Grumpy Old Man
Staff member
Moderator - World Affairs
Here's the article

1. Designed and created three main category (closed to a hundred) sound dampening equipments:

Created soft connectors for pipes and other equipments

Created air cushion based vibration dampening equipment that can withstand 25 atmosphere pressure and has maximum load bearing of 50 tons

Created low noise propeller shaft.

2. Increase the level of sophistication of vibration reduction technologies

Created the first gen (double layer of shock absorber) and second gen (floating raft) of vibration reduction tech.

Incorporated "Smart" tech (automatic load balancing, fault diagnosis, self tissue repair management, etc) into third gen vibration reduction tech (air cushion)

Reduced low frequency sound generated by the propeller shaft.

Working on fifth gen that leverage maglev tech

3. Created sub noise monitoring equipment (for testing purpose?)

4. Help to reduce equipment noise on islands in the South China Sea, increase the comfort level of troops stationed there.

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何琳,男,舰船声隐身技术专家,教授、博士生导师,专业技术少将。1957年11月生于陕西西安,籍贯四川西充。1987年5月加入中国共产党。1981年12月毕业于西安矿业学院,获工学学士学位。1984年6月毕业于海军工程学院,获工学硕士学位并留校。历任助教、讲师、副教授、教授、博士生导师、海军工程大学振动与噪声研究所所长、潜艇声隐身技术国防科技重点实验室副主任兼学术委员会副主任、国防科技大学兼职教授等职。中国声学学会理事,湖北省声学学会副理事长,中国造船工程学会军船学术委员会抗冲击学组副组长,总装备部隐身技术专业组成员,海军潜艇声隐身技术专家组副组长,《噪声与振动控制》期刊编委,轮机工程国家重点学科带头人。

作为军队潜艇减振降噪技术首席专家,多型潜艇减振降噪系统副主任设计师,在该领域持续开展了近30年基础理论研究、关键技术攻关和重大装备研制,实现我国在该技术领域系列创新,多项技术已达到或超过国际先进水平。研究成果全部实艇应用,为降低我国潜艇噪声起到决定性支撑作用。获国家科技进步二等奖2项,发明专利5项,出版专著2部,发表论文/国防报告148/16篇,荣立二、三等功各2次。

一、在舰用减振元器件技术领域,自主研制出三个系列近百种规格的舰用减振元器件,填补了多项空白。

1、突破发达国家对我国的技术封锁,在无任何资料借鉴情况下,靠自主创新,攻克理论、结构、材料、工艺和试验等多项难题,发明并研制出具有我国自主知识产权的三种系列潜艇用减振挠性接管,获3项发明专利。其中,肘形高压平衡式减振挠性接管技术为国内外首创,振动隔离指标超过国际上现有技术水平。系统解决了我国潜艇海水管路系统安全与减振抗冲设计的重大关键技术难题,已作为一项重要的减振降噪技术成果推广应用,2009年获国家科技进步二等奖。

2、发明并研制出工作压力25个大气压,最大承载能力50吨的系列舰用强载气囊隔振器,使我国舰用隔振器承载能力提升了一个数量级,填补国内空白,获国家发明专利,解决了舰船狭小空间内数百吨级大型隔振装置无减振器可用的重大难题。已大量应用。

3、发明并研制出新型低噪声螺旋桨轴承,解决了潜艇低速隐蔽航行时螺旋桨轴承高频异常强线谱噪声的控制难题,彻底消除了潜艇在作战机动过程中因该异常噪声而导致声学暴露的重大隐患。已大量应用。

二、在舰用减振装置技术领域,一直引领着国内该领域技术的发展。

1、率先研制出我国第一代和第二代隔振装置技术——双层隔振装置和浮筏隔振装置,解决了潜艇狭小空间内数十吨级以下单台或多台组合机械设备的高效隔振难题,获军队科技进步二等奖和湖北省科技进步二等奖各1项;已大量应用。

2、在国际上率先提出了智能隔振装置的技术概念,并建立了完整的设计理论体系,研制出具有完全自主知识产权的第三代隔振装置技术—大型智能气囊隔振装置,这是世界上首台智能化的隔振装置,具有自动负载平衡、故障自诊断、自组织修复管理等传统隔振装置一直无法实现的功能,解决了潜艇狭小空间内数百吨级大型动力系统振动的高效隔离难题,是我国目前控制潜艇动力系统机械噪声最有效的技术,实现了对发达国家技术的追赶和超越,2012年获发明专利,已全面应用。

3、突破推进动力装置低频隔振这一国际公认技术难题,在国际上首次研制出具有对中姿态监测、控制和保护管理等功能的第四代隔振装置技术——舰船推进动力系统低频隔振装置,实现隔振装置技术重大跨越。2012年获国家科技进步二等奖;已全面应用。

4、正在开展第五代隔振装置技术——“磁悬浮主被动混合隔振技术”(探索一代重大项目)的应用转化研究,可实现潜艇狭小空间内动力机械宽频和线谱振动的同步控制,消除潜艇的声指纹特征,已申报国家发明专利。

三、独立提出并建立潜艇“动态声隐身”技术的概念和理论框架,研究作战航行中潜艇声学特征的检测、评估与控制修复技术,开辟了潜艇隐身领域研究新方向。在一片空白情况下,2005年带领“国家队”,从无到有研制出我国第一代潜艇噪声监测系统,迈出潜艇隐身领域信息技术应用的第一步,达到国外同类装备技术水平,成果已全面应用。

四、作为工程总指挥组织完成了我国南沙各岛礁守礁官兵生活环境的噪声综合治理,使南沙守礁官兵的主要学习、生活区的环境噪声达到城市高档社区夜间休息环境质量,受到海军首长和守礁官兵的一致好评。此外,还组织完成了某型潜射战略导弹测试平台的高精度振动控制工程,成功解决测试间振动噪声超标重大技术难题,对提高导弹命中精度具有重要意义。

上述成果为我国舰船隐身技术进步起到重大支撑作用,为提高海军舰船,特别是潜艇装备水平和作战能力做出了重大贡献。新的成果已在后续型号上被陆续应用,将支撑我国新型潜艇及水面舰艇安静性能的持续提升。

何琳教授所取得的科技成就具有三个明显特点:一是全部科研成果均是自主创新的,具有完全自主知识产权;二是研究成果均处于国内领先水平,部分技术已达到国际先进水平;三是全部成果均在新型舰船上大量推广应用。

2009年选为全军高层次科技创新领军人才培养对象;2010年获全军杰出专业技术人才奖;2012年获马大猷声学奖,全国优秀科技工作者;在10多年时间里把一个5人科研小组发展为20多人科研团队,达到我国潜艇降噪技术研究最前沿,2011年被批准联合成立“潜艇声隐身技术国防科技重点实验室”,2012年荣立集体二等功,获中国人民解放军科技创新群体奖。共培养硕士29名、博士26名,指导博士后2名。2013年1月,中央军委习近平主席签署通令授记二等功。
 

vincent

Grumpy Old Man
Staff member
Moderator - World Affairs
Have to dig through CDF for my old posts

An article on the achievement of a professor specialized in naval quieting technologies

The sounds from submarines came from three main sources: machinery, propeller and water flow against the hull

The noises generated from machinery can be reduced by placing equipment on vibration dampening layers. Professor He Lin designed four generations of vibration dampening layers and working on the fifth gen.

The earliest effort is to insert soft materials between the equipments and the deck. First generation of vibration dampening layer consisted of two layers of shock absorber with some solid base in between and they are placed under individual equipments. Second gen increase the size of the layers to hold multiple equipments. The third gen based on air cushion increased the load bearing capability to several hundred tons and incorporated "Smart" tech. Fourth gen sound dampening equipment involved reducing the vibration of the propeller shaft.

Professor He also designed soft connectors for pipes to reduce vibration transmission.

He is working on reducing the "signature" sound of individual subs, making the sound as close to white noise as possible

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发布日期:2014-1-19

本刊记者 周方彤

  10月28日,我国首支核潜艇部队解密,中国海军公开大批核潜艇部队的照片,一时引起广泛关注。潜艇一直是现代军舰中最神秘的舰种,它靠自身的隐蔽性消灭敌人,然而这样一个神出鬼没的“水下杀手”却有着一个致命的弱点——噪声,一旦被发现就会被消灭。
  美国核潜艇之父海曼·里科弗曾经说过,让潜艇安静下来,远比造出核动力装置要复杂。潜艇降噪为什么会如此复杂?潜艇降噪的难度究竟在哪儿?2013年何梁何利基金科学与技术进步奖获得者、海军工程大学某研究所所长何琳为我们揭开了潜艇降噪之谜。

潜艇降噪研究

  1981年,何琳以优异的成绩考上了海军工程学院轮机工程专业的研究生,师从施引教授。从此,与潜艇减振降噪技术结下不解之缘。
  潜艇降噪是短板效应,只要有一个噪声源没有消掉,降噪效果就会大打折扣,“要想降噪就必须全部都降”。除此之外,降噪的另一大难点体现在随着噪声的降低,要控制的噪声源数量会不断增加。从能量的角度,潜艇要有效实现声隐身,就需要把潜艇辐射的水声能量从1瓦降低到百万分之几的微瓦量级,降噪难度可见一斑。
  潜艇的噪声来源主要有三个:最主要的来源就是潜艇上的机械设备,机械噪声是潜艇的第一大噪声源;第二大噪声源就是螺旋桨,螺旋桨推动潜艇前进会发出很大的噪声;第三大噪声源是流噪声,即水流流过潜艇激发出的噪声。在潜艇低速隐蔽航行时,螺旋桨和流噪声很小,潜艇航行能达到的最低噪声水平是由机械噪声决定的,要实现潜艇声隐身首先要降低潜艇的机械噪声。
  何琳的主攻研究就是控制潜艇的机械噪声。“要解决机器噪声的问题,原理很简单,最理想的状态就是让所有的机器都不发声,但这是做不到的。而且潜艇上的机器都是功率很大的动力设备,稍微一点点的振动能量漏出去,都能产生很强的噪声。另一个办法就是,我让机器的振动不传出去。”说到这里,何琳又举了个形象的例子,“把机器放到楼板上整栋楼都会响,但是如果把机器放在柔软的床垫上,振动噪声就很难传递出去了。机器隔振也是这个道理。”
  遵循着这个简单的原理,早期的减振技术就是在机器与艇体间插入柔性连接,如木头、橡胶材料等。但这远不能满足潜艇声隐身对机械振动的控制要求,第一代高效减振技术采用了双层减振,机械设备通过第一层减振器、中间基座、再一层减振器与艇体连接。这是美国人的早期发明,何琳的导师是国内最早跟踪研究这项技术的专家。但是这个装置存在明显的局限性:如果每一台设备都采用一个双层隔振,势必会增加太多的重量,占用过多的空间。美国很快就将这种技术发展成为组合式的隔振装置,即一个中间基座上安装多台机械设备,这就是第二代的浮筏隔振技术。何琳团队紧跟国外的技术发展,在国内最早研制出第二代浮筏隔振装置并得到广泛应用。
  然而,矛和盾总是在不断发展的,“我们平时说的听不见噪声指的是人的感受,而面对先进的探测仪器时你就会发现,所谓听不见和仪器探测不到有很大的差距”。
  要进一步降低潜艇的噪声,就必须对所有机械设备进行有效隔振。将潜艇上几百吨的机械设备集中隔振会获得更好的隔振效果,但难度相当大,首先面临的问题就是国内缺乏与之匹配的隔振器技术。“这个技术实际困扰着我们怎样把它做大。艇上的主要动力设备都很重,一个重量不大的设备,我能隔振,但是要做到把几百吨重的东西隔振就是一个量变到质变的问题。”
  当时,隔振技术停留在第二代上很难突破,何琳与团队都很焦急,“如果不能解决这个问题,潜艇最大的噪声源就没法控制,现有技术控制了小噪声源,但是没用,最大的噪声源没控制住就等于零”。
  功夫不负有心人。在何琳与团队的努力下,创新研制出具有国际先进水平的超大载荷气囊隔振器,并开发出第三代智能隔振装置技术,使隔振装置的承载能力达到数百吨级的水平,隔振效果接近了极限。更重要的是该技术首次使隔振装置具有智能功能,属国内外首创,实现了对国外先进技术的追赶和超越。
  减振的难题永远是一个接着一个。何琳又把目光瞄向了隔振技术领域公认的难题——推进动力装置的高效隔振。经过数年的努力,何琳团队凭借多项技术和理论的创新成果,成功地解决了推进动力装置高效隔振与推进轴系高精度动态对中的难题,在国内外首次研制出动态对中精度在几丝到十几丝的精度范围内,具有高安全机制的第四代隔振装置。2012年何琳在香港国际会议上介绍了这项技术,引起了很大轰动。
  解决了潜艇动力机械的高效隔振难题,何琳与团队又将目光投向了机械噪声第二声通道的控制上。潜艇上的多数机械设备都要跟管路连接在一起,这些管路又与艇体连接,这就形成了机械噪声向艇体传递的又一条通道,若不能有效控制将导致隔振装置与艇体间声短路。国内曾在俄罗斯发现其采用了一种平衡式挠性接管,这种挠性接管能有效地解决机器上的管路和艇体间的声短路问题,但对方拒绝向我国出口该技术。该接管的技术要求很高,既能耐高压又要有柔性,能承受很高的内压,而且不能变形。“就像一个奇特的气球,它是软的,但吹气后还不能膨胀。”这个问题困扰着何琳团队,解决不了这个问题,振动隔离得再好,噪声也会通过管路旁通出去。经过三年多的研究,何琳团队最终成功解决了这个难题,研制出具有我国自主知识产权的系列产品。

创新引领未来

  多年来,何琳带领团队创新,瞄准部队装备急需,先后研制开发出7个系列数百种规格具有完全知识产权的新型高性能减振元件,实现了潜艇隔振装置的4次技术跨越。而何琳的团队也从最初的数个人,扩充到现在的数十人规模,同时,他们还与工业部门联合建成了国防科技重点实验室。
  如今何琳的创新团队科研模式已经进入了良性循环,他门开展的所有技术研究都是国内最先进的。“做高水平的技术研究,提升了竞争门槛的同时也更好地激励团队创新。”何琳坦言,团队几乎所有的技术都是自主创新的,“做前人没有做过的,或者做不到的,有创新才有发展。”而最令何琳自豪的是,他们的所有技术都是从最初的想法一直做到产品,并且全部实现了技术的转化和应用。
  去年,何琳被中国声学学会授予“马大猷声学奖”,他率领的创新团队获得“军队科技创新群体奖”,并被海军记集体二等功。何琳先后获国家科技进步奖二等奖、军队科技进步奖一等奖及二等奖多次。近几年获得的诸多奖励其实也是何琳与团队多年科研积累的成果。面对这些荣誉,何琳说:“很多东西其实是水到渠成的,只要我们一直在做这些研究,获奖只是早晚的问题。我更希望能将更多的精力投到研究上。”未来,为了应对先进仪器的高精度探测,何琳与团队将瞄准更高难度的潜艇隐身技术,让有特征的潜艇噪声成为“白噪声”,让噪声成为无法被识别的声音,完成真正的潜艇隐身。他们提出的潜艇动态声学特征管理技术研究将“使潜艇实现在作战航行状态下的真正隐身。这是我们追求的终极目标”。

人物档案
  何琳 1957年11月出生,四川西充人,海军工程大学某研究所所长、教授、博士生导师,少将军衔,享受国务院政府特殊津贴,军队杰出专业技术人才,全国优秀科技工作者。2013年,获何梁何利科学与技术进步奖,2012年,被中国声学学会授予“马大猷声学奖”,其率领的创新团队获得“军队科技创新群体奖”,并被海军记集体二等功。先后获国家科技进步奖二等奖2项、发明专利3项,军队科技进步奖一等奖2项、二等奖2项。荣立二等功1次,三等功2次。
 

Hendrik_2000

Lieutenant General
Thanks vincent great stuff As I said before they put it on the vibration raft and use air cushion to damp it then they work on active cancellation . Improve the propeller design
 
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