JPS60209389A - Cavitation warning device of warships and other vessels - Google Patents
Cavitation warning device of warships and other vesselsInfo
- Publication number
- JPS60209389A JPS60209389A JP59066149A JP6614984A JPS60209389A JP S60209389 A JPS60209389 A JP S60209389A JP 59066149 A JP59066149 A JP 59066149A JP 6614984 A JP6614984 A JP 6614984A JP S60209389 A JPS60209389 A JP S60209389A
- Authority
- JP
- Japan
- Prior art keywords
- propeller
- cavitation
- rotational speed
- speed
- rotation speed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
【発明の詳細な説明】
〔発明の技術分野〕
この発明は、航行中のプロペラ回転数及び船速を用いて
リアルタイムにプロペラキャビテーショ（１）
ン発生の臨界回転数をめ、現在の本船のプロペラ回転数
と比較し９本船のプロペラ回転数がプロペラキャビテー
ション発生の臨界回転数を越えていれば、警報装置によ
り操船者に警報を発する装置に関するものである。[Detailed Description of the Invention] [Technical Field of the Invention] This invention calculates the critical rotation speed for propeller cavitation (1) in real time using the propeller rotation speed and ship speed during navigation, and This invention relates to a device that issues a warning to a vessel operator using an alarm device if the propeller rotation speed of a ship exceeds the critical rotation speed for generating propeller cavitation compared to the propeller rotation speed.
従来航行中に本船のプロペラがキャビテーションを発生
しているか否かは、プロペラのキャビテーションが激し
く騒音が著るしいような場合に操船者が経験的に判断す
る以外に方法がない。Conventionally, the only way to determine whether or not cavitation is occurring in the propeller of a ship during navigation is for a ship operator to judge empirically when the propeller cavitation is severe and the noise is significant.
すなわち、従来プロペラキャビテーションが激しく、騒
音が著るしかったシ船体振動が激しくなるなど、物理的
現象が起きた場合、操船者が経験的にプロペラキャビテ
ーションと判断しており。In other words, when propeller cavitation has traditionally been intense, causing significant noise and physical phenomena such as increased hull vibration, vessel operators have empirically determined that it is propeller cavitation.
客観的に判断する方法がない。したがって、キャビテー
ションが発生しても操船者が気付かなかったシ、また騒
音や振動に気付いても操船者がプロペラキャビテーショ
ンに対する知識が充分でないと、そのまま放置される場
合がある。There is no way to judge objectively. Therefore, even if cavitation occurs, the boat operator may not notice it, or even if the boat operator notices noise or vibration, it may be left as it is if the boat operator does not have sufficient knowledge about propeller cavitation.
プロペラキャビテーションが発生すると騒音や（２）
船体振動が生ずるばかシでなく、プロペラ効率の低下や
エロージョンによるプロペラの損傷等その影響は大きい
。When propeller cavitation occurs, it not only causes noise and (2) vibration of the ship's hull, but also has major effects such as a decrease in propeller efficiency and damage to the propeller due to erosion.
この発明はこれらの欠点を除去するために２本船の航行
中のプロペラ回転数及び船速を用いてリアルタイムにプ
ロペラキャビテーション発生の臨界回転数を計算し、現
在の本船のプロペラ回転数との比較を行い、その比が一
定値以上になると。In order to eliminate these drawbacks, this invention calculates the critical rotation speed for propeller cavitation in real time using the propeller rotation speed and ship speed of the two ships during navigation, and compares it with the current propeller rotation speed of the main ship. and when the ratio exceeds a certain value.
キャビテーション発生中であることを操船者に知らせる
ため警報装置により警報を発するようにしたものである
。An alarm device is used to issue an alarm to notify the vessel operator that cavitation is occurring.
以下図面について詳細に説明する。 The drawings will be explained in detail below.
図はこの発明によるシステム構成図を示す。The figure shows a system configuration diagram according to the present invention.
プロペラ軸に取り付けられた回転計（１）によシ検出さ
れたプロペラ回転数ｔ２）ならびにログ（３）により検
出された船の速力（４）は、Ｓ／Ｄ変換装置（５）によ
りシンクロからディジタルに変換され、演算装置（６）
に入力される。The propeller rotation speed (t2) detected by the tachometer (1) attached to the propeller shaft and the ship's speed (4) detected by the log (3) are synchronized by the S/D converter (5). Converted to digital and arithmetic device (6)
is input.
（３）
演算装置（６）には、プロペラキャビテーション発生の
臨界回転数をめるチャート又は計算式を保有する。(3) The arithmetic unit (6) has a chart or calculation formula for determining the critical rotational speed for propeller cavitation to occur.
プロペラキャビテーション判定方法については種々の方
法が提案されているが、採用したプロペラタイプに合っ
たチャート又は計算式を使用するとともに、模型プロペ
ラでキャビテーション試験が実施されていれば、それら
の結果によシ補正係数を用いるのが望ましい。Various methods have been proposed for determining propeller cavitation, but in addition to using charts or calculation formulas that match the propeller type adopted, if cavitation tests have been conducted on model propellers, the results can be used for simulation. It is desirable to use a correction factor.
一般商船では古くから良く使われている方法としてＢＵ
ＲＲＩ ＬＬ−ＮＳＭＢの図表、ＥＧＧＥＲＴの方法や
中高博士の計算式がある。BU is a method that has been well used in general merchant ships for a long time.
There are RRI LL-NSMB charts, EGGERT's method, and Dr. Nakataka's calculation formula.
一例として中高博士の計算式によると、プロペラキャビ
テーション発生の臨界回転数ｎｃはｎυ
但し、Ｐｓ：プロペラ翼端の静圧
（４）
ｅ：蒸気圧
ｆ：海水密度
Ｄ：プロペラ直径
（ｒ／Ｒ）：プロペラ中心からの半径方向位置Δｐ／ｑ
：揚力係数に対応した最大圧力低下量（１−ｗ）：船の
伴流係数
Ｖ ＝船の速力
ｎ：プロペラ回転数
上記係数は船体形状及びプロペラ特性によって決まる値
で、あらかじめデータを入力しておくことによシ、航行
中のか及びｎが得られればＮＣは容易にめられる。As an example, according to Dr. Nakataka's calculation formula, the critical rotational speed nc for propeller cavitation occurrence is nυ However, Ps: Static pressure at the tip of the propeller blade (4) e: Vapor pressure f: Seawater density D: Propeller diameter (r/R) : Radial position Δp/q from propeller center
: Maximum pressure drop corresponding to lift coefficient (1-w): Ship's wake coefficient V = Ship's speed n: Propeller rotation speed The above coefficients are values determined by the hull shape and propeller characteristics, and the data must be entered in advance. If you can obtain the current value and n of the ship under navigation, you can easily determine the NC.
すなわち航行中宮にｎ／ｎ（を計算し、ｎｌ／ｈｃがあ
る値を超えたら警報装置（７）により警報を発する。That is, n/n( is calculated for the navigating shrine, and if nl/hc exceeds a certain value, an alarm is issued by the alarm device (7).
以上のようにこの発明によれば、リアルタイムに航行中
のプロペラ回転数がプロペラキャビテーション発生の臨
界回転数を超えているかどうかをチェックし、超えてい
ればキャビテーションが現在発生中であると判断し、操
船者に警報を発令す（５）
る。As described above, according to the present invention, it is checked in real time whether the propeller rotation speed during navigation exceeds the critical rotation speed for generating propeller cavitation, and if it is, it is determined that cavitation is currently occurring. Issue a warning to the vessel operator (5).
操船者はこの警報によシ、エンジン出力を下げたり、可
変ピッチプロペラであればプロペラピッチ角を変えるこ
とによシ、すみやかにプロペラキャビテーションの発生
をさけることができる。In response to this warning, the operator can promptly avoid propeller cavitation by reducing the engine output or, in the case of a variable pitch propeller, by changing the propeller pitch angle.
図はこの発明のシステム構成図を示す。
図において（１）は回転計、ｔ２）はプロペラ回転数、
（３）はログ、（４）は船の速力、（５）はＳ／Ｄ変換
装置、（６）は演算装置、（７）は警報装置である。
代理人大岩増雄
（６）The figure shows a system configuration diagram of the present invention. In the figure, (1) is the tachometer, t2) is the propeller rotation speed,
(3) is a log, (4) is the speed of the ship, (5) is an S/D converter, (6) is a calculation device, and (7) is an alarm device. Agent Masuo Oiwa (6)
Claims (1)
ロペラ回転数及びログによシ検出された本船の速力をデ
ィジタル変換するためのジΦ変換装置と、これらのデー
タを用いてプロペラキャビテーション発生の臨界回転数
を計算する演算装置と、警報装置とで構成され、航行中
のプロペラ回転数及び速力を用いてリアルタイムにプロ
ペラキャビテーション発生の臨界回転数を計算し、現在
の本船のプロペラ回転数の比較を行い、その値が一定値
以上になると警報を発生し、操船者に知らせることを特
徴とする艦船のキャビテーション警報装置。A digital Φ conversion device is used to digitally convert the propeller rotation speed detected by a tachometer attached to the propeller shaft and the ship's speed detected by logs, and this data is used to detect the occurrence of propeller cavitation. Comprised of a calculation device that calculates the critical rotation speed and an alarm device, it calculates the critical rotation speed for propeller cavitation in real time using the propeller rotation speed and speed during navigation, and compares the current propeller rotation speed of the ship. A cavitation warning device for a ship is characterized in that when the value exceeds a certain value, it generates an alarm and notifies the operator of the ship.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59066149A JPS60209389A (en) | 1984-04-03 | 1984-04-03 | Cavitation warning device of warships and other vessels |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59066149A JPS60209389A (en) | 1984-04-03 | 1984-04-03 | Cavitation warning device of warships and other vessels |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60209389A true JPS60209389A (en) | 1985-10-21 |
Family
ID=13307516
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59066149A Pending JPS60209389A (en) | 1984-04-03 | 1984-04-03 | Cavitation warning device of warships and other vessels |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60209389A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010095018A (en) * | 2008-10-14 | 2010-04-30 | Eisaku Mano | Marine vessel |
| US9545987B1 (en) | 2014-05-02 | 2017-01-17 | Brunswick Corporation | Traction control systems and methods for marine vessels |
-
1984
- 1984-04-03 JP JP59066149A patent/JPS60209389A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010095018A (en) * | 2008-10-14 | 2010-04-30 | Eisaku Mano | Marine vessel |
| US9545987B1 (en) | 2014-05-02 | 2017-01-17 | Brunswick Corporation | Traction control systems and methods for marine vessels |
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