潜艇系列 之 水下听音器

jt1981

如今随着sh4的汉化发布，更多的朋友加入到来猎杀的游戏中来，，不管是玩sh3还是sh4的玩家都应该对潜艇以及潜艇上的设备有个了解，这样才能知己知彼，百战百胜啊，本人就是在www.uboat.com上发现来一些英语介绍对一些初级玩家有帮助的资料介绍，现在将英文与翻译过来的资料拿出来让大家分享。

本次是第一部分翻译，，使用来uboat网站的关于水听器的介绍文章。

Underwater sound detector in WW1 and WW2
by Robert Derencin
1. Introduction
Underwater sound detector is a hydro acoustic device intended to separate target's sound waves from sound waves of environment. In this case, the target is a surface ship or a submarine, and the environment is an ocean. The ultimate intention is to detect being of any object (a ship or a submarine) in the vicinity of the underwater sound detector and, if that is possible, direction and range of the object.
2. Ship's (submarine's) acoustic field
Ship's acoustic field is a space in which the ship's noises can be detected. A total ship's acoustic field is a sum of all acoustic components. The components depend about ship's type and individual characteristics (number and shape of her propeller, shape of her underwater part, grade of her axis and mechanism balance…), about ship's displacement and speed. A submarine acoustic field depends also about depth of the submarine.
Main noises inside ship's acoustic field are:
- ship's engines noises (main and auxiliary engines, axis vibration, outflow of fluids…)
- ship's hull noises (skin friction between water particles and ship's hull plating)
- propeller noises (propeller-excited vibrations plus cavitation)
There aren't two ships (or two submarines) with same noise. There are some characteristics ship's noises:
- low speed propeller- more low frequency than high frequency noises,
- high speed propeller- more high frequency than low frequency noises,
- more numbers of propellers- more high frequency than low frequency noises,
- minesweepers- noises mostly between 300 to 400 Hz.
There are differences from ship to ship about noise's frequency and sound pressure. Depending about ship's speed, the same ship can produce different noises. Table 1 shows various kinds of frequency of noises and sound pressure depending about ship's type and speed.
Table 1:
Ship type        Ships's speed        Frequency of noises        Sound pressure
Minesweeper        28 knots        200 - 400 Hz        1200 bar
Minesweeper        4.6 knots        100 - 200 Hz        3 - 4 bar
Minesweeper        26 knots        100 - 200 Hz        240 - 250 bar
Torpedo boat        26 knots        200 - 400 Hz        Less than 10 bar
3. Underwater sound detector in WW1
In World War One about 3000 Allied counter submarine ships were equipped with underwater sound detectors. It is considered that the first submarine detected by underwater sound detector (and destroyed by surface ship) was German submarine U-3 in English canal. In October 1914 German submarine U-27 destroyed British submarine E-3. It was the first time that one submarine destroyed another submarine. From 1917, almost all British submarines were engaged in fight against German submarines. Because of that, the British submarines were equipped with underwater sound detectors.
The first underwater sound detectors functioned by principle of "sound shadow". Two hydro-phones were mounted on underwater part of a ship's bow, each hydro-phone on each side of the bow.
Captured underwater noise was transmitted directly from the hydro-phone to operator's ear-phones. The each ear-phone was connected with the one hydro-phone. By strength of noise in particular ear-phone, the operator detected from which side (starboard or port side) the noise coming. The ship turned round until the noise was now same in booth operator's ear-phones. When the noise was same in the both ear-phones the ship's crew knew that the ship is on course to the source of the noise, i.e. to the submarine. Range of that first underwater sound detectors was up to 4 nautical miles, accuracy was from 15 to 20 degrees.
To avoid her own noises, when the underwater sound detector was in function the ship had to be stopped. Picture number 1 shows principle of the underwater sound detection mentioned above. Submarine's signal are louder in hydro-phone number 2 than in hydro-phone number 1. Because of that, in ear-phone which is directly connected with the hydro-phone number 2, will be louder signal, too. The sound detector operator will know on which side of the ship the submarine is positioned.
Picture 1:

The first hydro-phones functioned on principle of magnetostriction or piezoelectricity. Mechanical vibrations of membrane, evolved from underwater noises, were converted into electric voltage, which was brought to the ear-phones. Underwater sound detectors based on binaural method (binaural- "for both ears") were installed in 1917. Their hydro-phones were mounted on a both ends of special handle, which was mounted on underwater part of a ship's bow. Distance between the hydro-phones had to be at least 0.95 metres. The underwater sound detector operator turned round the handle, around the handle's centre, until a detected noise was not same in both ear-phones. Range of detecting was enlarged. Accuracy was from 3 to 4 degrees. Underwater sound detectors based on binaural method were also used in WW2.
Picture 2:

Picture number 2 shows scheme of underwater sound detector used in United States navy during WW2.
1- binaural hydro-phone
2- handle for the hydro-phone's revolution
3- axis
4- noise amplifier
5- super heterodyne amplifier
6- loud speaker or ear phones

4. Underwater sound detector in WW2
There were some improvements of the underwater sound detectors between WW1 and WW2. Hydro-phones based on electrodynamic and piezoelectricity have been introduced. Electric compensator enabled detection of direction without revolving of the hydro-phones. Numbers of the hydro-phones of particular underwater sound detector were increased. Also, underwater sound detection by principle of interference has been applied. By the principle of interference a ship's or a submarine's own noises had less influence. Because of that, accuracy of detecting was from 2 to 3 degrees, range of detecting was more than 10 nautical miles.
In WW2 the underwater sound detectors were installed on the submarines of all involved navies. The underwater sound detector consisted of:
acoustic system: group of piezoelectric hydro-phones (up to 24 hydro-phones) who changed sound vibrations into electric energy,
compensator: engaged detecting of sound's (i.e. target's) direction without revolving the hydro-phones,
amplifier: amplified received signals (noises),
indicator: cathode tube, loudspeaker or ear-phones.
Some underwater sound detectors had also a filter for choice of wave (i.e. noise's) band, mostly to avoid own noises.
Possibilities of underwater sound detecting in WW2:
Experienced underwater sound detector operator was able to determine is a detected ship a cargo ship or a warship (type of the warship), approximate speed or manoeuvre of the ship (approaching, digression, increasing or decreasing of speed and depth, if detected object was a submarine).
When detected (submerged) submarine stopped her moving, the operator was able to determine which mechanisms of the submarine still operated. To avoid own noises, a submarine could use underwater sound detector if her speed was up to 6 knots. If a submarine speed was 4 knots, the submarine's underwater sound detector average distance of detecting another object was:
- for a destroyer- 5 to 10 nautical miles,
- for a cargo ship- 3.5 to 7.5 nautical miles,
- for a convoy- up to 50 nautical miles.
If a submarine speed was 15 knots, the submarine's underwater sound detector possibility of detecting another object was rapidly decreased [although no submarines except XXI and XXIII were able to reach that speed during WWII]. In that case, average distance of detecting another object was up to few hundred metres.

5. Definitions of some technical expressions mentioned in the article
Cavitation. The rapid formation and collapse of vapor pockets in a flowing liquid in regions of very low pressure, often a frequent cause of structural damage to propellers, pumps, etc.
Electrodynamic. Pertaining to the force of electricity in motion.
Hydrophone. A device for locating sources of sound under water, as for detecting submarines by the noise of their engines.
Magnetostriction. A change in dimensions exhibited by ferromagnetic materials when subjected to a magnetic field.
Piezoelectricity. Electricity, or electric polarity, produced by mechanical pressure on a non conducting crystal.
Heterodyne. Noting or pertaining to a method of changing the frequency of an incoming radio signal by adding it to a signal generated within the receiver to produce fluctuations or beats of a frequency equal to the difference between the two signals.

6. Conclusion
In WW2 active sonar (Asdic) was fitted on a surface ships. It was so because the surface ships didn't care if submarines knew for their presence or not. Even better, presence of surface ship (a destroyer or a patrol craft, for example) caused giving up of submarine attack. Also, with the active sonar (Asdic) it was possible to determine range between the surface ship and submarine.
Passive sonar (Underwater sound detector) in WW2 was fitted on submarines. The submarines were able to detect presence of surface ships (and another submarines) in their vicinity, and the submarines stayed undetected. But, those days, passive sonar wasn't able to determine range of another ships or submarines.
Today, the sonar fitted on surface ships or submarine can work in both mode, passive mode and active mode. But today even passive mode working sonar can determine range of another object (a surface ship or a submarine). What is more important, if the submarine sonar is working in the passive mode, the submarine will stay undetected.
And, don't forget that the first task of any submarine is to stay undetected.
This article was published on 25 Jan, 2003
























水下听音器
1.        介绍
水下声音探测器也就是水听器是用来分离目标生源和环境生源的。换句话说，目标就是指水面舰艇或潜艇，而环境就是指海洋。它的最终目标就是要探测出附近的目标（包括舰艇或潜艇），当然如果可能的话，还有目标的方位以及距离。

2.舰艇（潜艇）的声场
舰船的声场就是指舰艇的噪声能被侦测出的区域。几乎所有船只的声场都是由一堆声音合成出来的。这些合成取决于船只的型号以及那些独特的规格参数（比如螺旋桨的数量以及形状，水线下部分的形状，轴的倾斜度数还有机械设备的平衡等等），舰船航速和排水量。潜艇的声场是由潜艇的潜深决定的。舰船声场的主要噪声源如下：
-舰船的引擎噪声（主辅引擎，轴的颤动，液体的流出量…）
-舰船外壳的噪声（船只外壳与海水碰撞摩擦）
-螺旋桨噪声（螺旋桨的颤动以及气窝现象）

没有两艘船只（包括潜艇）拥有相同的噪音。以下是船只噪声的具体参数特点：
-低速螺旋桨-由于频率较低噪声也较小
-高速螺旋桨-频率高噪声大
-大量螺旋桨-频率高噪声大
-扫雷舰-噪声频率介于300到400之间

船与船之间有着不同的噪声频率和声压。这个基本就取决于船只的航速，同一艘船可以发出不同的噪声。表1显示了不同船只在不同航速下发出的频率和声压
表1：
船只类型        船只航速        噪声频率                         声压
扫雷舰        28节        200-400赫兹        1200巴
扫雷舰        4.6节        100-200赫兹        3~4巴
扫雷舰        26节        100-200赫兹        240~250巴
鱼雷艇        26节        200-400赫兹        小于10巴

3.一战中的水下声音探测器
一战中，大约有3000艘盟军反潜舰装备来水下声音探测器。公认的是第一艘被水下探测器发现的潜艇是德军U-3号潜艇，当时正在英国水道巡逻。1914年10月德国U-27号潜艇击沉了英国E-3号潜艇。这是世界上第一个潜艇击沉潜艇的战例。从1917年开始，几乎所有英国潜艇都被部署到对抗德国潜艇的战斗中。也正因为这个原因，英国潜艇均配备来水下声音探测器。

第一代基于“声影”原来工作的水下声音探测器。两个水听器装设在舰船艇艏的水下部分，每边各装有一个。

水听器将捕捉到的水下噪声传递到操作员的耳机中。每只耳机连接着一只水听器。通过噪声的强弱，操作员就可以分辨出生源的具体方位（是来自左舷还是右舷）。舰艇开始转向直到生源在操作员的两个耳机中强弱相同为止。当噪声在两个耳机中一样来，那么就意味着舰船正在驶向噪声方位，也就是潜艇的方位。第一代水下探测器的有效距离大概是4海里左右，精确度为15~20度。

为了避免受到自己的噪声影响，当水下声音探测器工作时舰船必须处于停车状态。图1表明来水下声音探测器的工作原理。2号水听器探测到潜艇的信号将比1号更强一些。而这个情况也将同样反映在操作员的耳机当中。水下声音探测器将会发现潜艇到底处于本艇的那一侧。
图1

第一代基于磁弹性或压电现象原理进行工作的水听器。机械的隔膜震动，水下噪声的进化，转换成了电压，而这种电压被送到来耳机里面。基于双耳方式的水下声音探测器在1917年装备部队。这种水听器固定在一个可旋转的把手上，而把手又固定在舰船吃水以下的艇艏部位。两只水听器间距不得小于0.95米。水听器操作员旋转把手，直到生源在两个耳机中不同为止。这样探测距离就增加来。精确度在3~4度之间。基于双耳方式的水听器在二战中也有使用。
图2

图2表示了二战中美军使用的水下声音探测器的设计方法
1-双耳水听器
2-旋转水听器的把手
3-轴
4-噪声放大器
5-超级外差放大器
6-扩音器或耳机

4.二战中的水下声音探测器
在一战和二战之间，水听器得到来部分改进。基于磁弹性或压电现象原理进行工作的水听器上文已经介绍过了。电力调相机可以让水听器不旋转也可以探测声源方位。而且水下听音器的数量也增加了。还有，基于干扰原理的水听器也被认可了。通过干扰原理船只或潜艇自身的噪声影响大幅度下降了。也正因为如此，探测精确度发展到了2~3度的误差，探测距离超过了10海里。
在二战中所有潜艇都安装来水下声音探测器。水听器的组成部分如下：
声音系统：由一组(大约24只水听器)压电水听器构成，它们可以将声音震动转化成电能。
调相机：可以让水听器不旋转也可以探测不同方位的声音。
放大器：将接受到的信号（噪声）放大
指示器：阴极管，扬声器或耳机

一些水听器甚至可以将波浪的波段进行过滤，这样可以极大的减少自身噪声带来的干扰。

二战中水听器的功能：
有经验的水听器操作员可以分辨出目标是货船还是军舰（甚至分辨出军舰的类型），目标的大概航速以及船只的行径（是接近还是远离，是加速还是减速，如果对方是潜艇还能读出它的深度。）

当被探测到的潜艇停车隐蔽时，操作员可以听到潜艇上那些还在运转机器的噪声。为了避免受到自身噪音的影响，潜艇可以用6节以下的航速并同时使用水听器侦测目标。如果潜艇航速4节，那么它用水听器可以探测到的目标距离如下：
-驱逐舰-5-10海里
-货船-3.5-7.5海里
-护航队-大概50海里

如果潜艇的航速超过15节，那么水听器对目标的探测能力将大幅度下降（当然在二战中除了德军的XXI和XXIII级潜艇外没有一艘潜艇在潜航时可以达到15节航速）。如果真的以15节航行的话，潜艇对目标的探测距离也就几百米而已。

5.文中提到的部分专业名词的解释
气窝现象：低压区域由于液体流动而快速形成并衰减的蒸汽真空带，通常是由于建筑受损后波及螺旋桨、水泵等造成的
水听器：一种用来寻找水下生源的装置，可以通过探测潜艇引擎发出的噪声来发现潜艇。
磁弹性：当铁磁材料遇到磁场时发生长度变化
压电现象：当机械压力施加于绝缘物质水晶上时产生的电或电极性

6.结论
在二战中水面舰艇安装来主动声纳。因为他们不在乎潜艇是否发现他们已经过来了。往好处想，水面舰艇的出现（驱逐舰或护卫舰）可能让潜艇放弃攻击。当然，使用主动声纳可以探测出潜艇和水面舰艇之间的距离。
二战中的被动声纳（水下听音器）常装在潜艇上。潜艇通过水听器可以发现他们附近的水面舰船（或者是别的潜艇），而潜艇自身并不会暴露。但是，在那时，被动声纳不能侦测距离。

如今，装在舰艇或潜艇上的声纳可以工作于两种模式，被动模式和主动模式。但是现在即使是被动模式工作的声纳也可以探测对方的距离。更重要的是，如果潜艇使用被动模式的声纳，他们可以保持隐蔽而不被发现。

还有，我们应该时刻牢记潜艇的首要任务就是要保持隐蔽。
本文于2003年1月25日发表，由jt1981于2009年1月26日翻译完毕。

jt1981

图片还没有发布，我之后会想办法补上的，有朋友有免费的好些的图片链接网址吗？推荐几个，谢谢！

ufohacker

貌似没有……帮顶下……………………………………………………………………………………………………

20080808

厉害

RingChan

很好。。。。我对此类知识很敢兴趣！！！

smsfdy

支持，支持，支持

sculida

你他娘的真是天才！