Matrix Games Forums

Forums  Register  Login  Photo Gallery  Member List  Search  Calendars  FAQ 

My Profile  Inbox  Address Book  My Subscription  My Forums  Log Out

Cavitation and Surface Vessels

 
View related threads: (in this forum | in all forums)

Logged in as: Guest
Users viewing this topic: none
  Printable Version
All Forums >> [New Releases from Matrix Games] >> Command: Modern Operations series >> Cavitation and Surface Vessels Page: [1]
Login
Message << Older Topic   Newer Topic >>
Cavitation and Surface Vessels - 10/26/2020 12:17:52 AM   
ProdigyofMilitaryPride

 

Posts: 93
Joined: 4/17/2015
Status: offline
From what I gathered, cavitation in real life can damage the propellers of ships. Is that true for the surface ships and subs in this game as well? I ask because it seems the safest speed for big surface ships like aircraft carriers can only go 8 knots without cavitating.

_____________________________

"The courageous must protect freedom." - Dwight D. Eisenhower
"Anything built by human hands can be destroyed. This is no exception." - Kei "Edge" Nagase, Ace Combat 5: The Unsung War
Post #: 1
RE: Cavitation and Surface Vessels - 10/26/2020 1:13:38 AM   
stww2

 

Posts: 54
Joined: 5/23/2017
Status: online
I have no idea what happens in real life, but cavitation in CMO will not cause any damage to the platforms cavitating. It will, however, make the cavitating platform much easier to detect on passive sonar.

(in reply to ProdigyofMilitaryPride)
Post #: 2
RE: Cavitation and Surface Vessels - 10/26/2020 1:16:07 AM   
ProdigyofMilitaryPride

 

Posts: 93
Joined: 4/17/2015
Status: offline
Thanks, stww2.

_____________________________

"The courageous must protect freedom." - Dwight D. Eisenhower
"Anything built by human hands can be destroyed. This is no exception." - Kei "Edge" Nagase, Ace Combat 5: The Unsung War

(in reply to stww2)
Post #: 3
RE: Cavitation and Surface Vessels - 10/26/2020 1:43:42 AM   
Rory Noonan

 

Posts: 2634
Joined: 12/18/2014
From: Melbourne, Australia
Status: offline
The forces involved in cavitation are actually quite impressive so it doesn't surprise me that cavitation causes damage to props over time. I would be surprised if they had a significant impact on performance in the timeline of a typical Command scenario though.

Detection by passive sonar, on the other hand, is vastly easier if the target is cavitating. This is expressly modelled in Command; and we also provide an AI option to avoid cavitation for this reason.

_____________________________


(in reply to ProdigyofMilitaryPride)
Post #: 4
RE: Cavitation and Surface Vessels - 10/26/2020 1:49:04 AM   
pbrowne


Posts: 95
Joined: 8/7/2020
From: Perth, Western Australia
Status: offline
Well the topic is on cavitation and surface vessels, but I have a question on cavitation, pump jet propulsion and submarines. Pump jet propulsion can significantly reduce cavitation and acoustic signature (link 2) and is being planned for use in large submarines such as the Australian Attack class Short Fin Barracuda SSG (link 1 and link 2) and the US Virginia class SSN. The Attack class is not scheduled to be phased in until 2030. China is also apparently developing rim-driven pump jet propulsion in their new Type 095 SSN.

Is there any modelling of pump jet propulsion in CMO to take account of this type of propulsion, especially in regard to virtually eliminated cavitation and reduced noise signature? E.g. for the current the Virginia, Astute, Triomphant and Borei class subs?

< Message edited by pbrowne -- 10/26/2020 6:13:42 AM >

(in reply to ProdigyofMilitaryPride)
Post #: 5
RE: Cavitation and Surface Vessels - 10/26/2020 8:55:34 PM   
Parel803

 

Posts: 201
Joined: 10/10/2019
From: Netherlands
Status: online
I think in real life cavitation has effect.
Your' NoCav speed goes down until there is hardly any,
Your' speed goes down 1 to 2 knots, in the end it can go up till 5 knots,
Due to vibrations it can damage you're propellor shafts and gear casing more noise, sonars like that.
with regards GJ









Attachment (2)

_____________________________


(in reply to pbrowne)
Post #: 6
RE: Cavitation and Surface Vessels - 10/26/2020 9:30:18 PM   
thewood1

 

Posts: 5201
Joined: 11/27/2005
Status: online

quote:

ORIGINAL: Parel803

I think in real life cavitation has effect.
Your' NoCav speed goes down until there is hardly any,
Your' speed goes down 1 to 2 knots, in the end it can go up till 5 knots,
Due to vibrations it can damage you're propellor shafts and gear casing more noise, sonars like that.
with regards GJ

I don't think there is an argument about cavitation causing damage to props. The question is over what period of time will a typical ship see damage from cavitation that effects performance. Does it have an effect over hours, days, weeks, etc.?

(in reply to Parel803)
Post #: 7
RE: Cavitation and Surface Vessels - 10/26/2020 10:04:46 PM   
Dimitris


Posts: 12651
Joined: 7/31/2005
Status: offline

quote:

ORIGINAL: pbrowne
Is there any modelling of pump jet propulsion in CMO to take account of this type of propulsion, especially in regard to virtually eliminated cavitation and reduced noise signature? E.g. for the current the Virginia, Astute, Triomphant and Borei class subs?


Yes, there is. It doesn't quite eliminate cavitation, but it does significantly raise the speed (per given depth) at which it starts happening. Shrouded propulsors are also quieter for a given speed and offer a slight advantage in acceleration.

_____________________________


(in reply to pbrowne)
Post #: 8
RE: Cavitation and Surface Vessels - 10/26/2020 10:18:48 PM   
BeirutDude


Posts: 1871
Joined: 4/27/2013
From: Jacksonville, FL, USA
Status: offline
We had to take the prop off the USS Iwo Jima (LPH-2) in Metro Shipyards, Portsmouth, VA and it looked very much like those pictures. During high speed runs (above 15 knots ) she would shake like a wet dog and in the aft portion of the ship you could feel the cavitation bubbles slap the blades! The other interesting part of that was the rudder pin needed to be replaced. They had to cut through three decks to get it out with a huge tripod crane and it was a huge Clevis Pin!

_____________________________

"Some people spend an entire lifetime wondering if they made a difference. The Marines don't have that problem."
PRESIDENT RONALD REAGAN, 1985

I was Navy, but Assigned TAD to the 24th MAU Hq in Beirut. By far the finest period of my service!

(in reply to Parel803)
Post #: 9
RE: Cavitation and Surface Vessels - 10/26/2020 11:18:17 PM   
HalfLifeExpert


Posts: 732
Joined: 7/20/2015
From: California, United States
Status: offline
Yeah I think damaged is caused to propellers, but it would be over a rather long period of time, far longer than the average scope of any CMO scenario.

(in reply to BeirutDude)
Post #: 10
RE: Cavitation and Surface Vessels - 10/26/2020 11:27:18 PM   
BeirutDude


Posts: 1871
Joined: 4/27/2013
From: Jacksonville, FL, USA
Status: offline
It takes years but a lot depends upon the blade of the prop. The old Iwo Jima just had a regular commercial merchant vessel type prop so it was pitted within a few years. They replaced it in 1982 and again in 1985. More efficiently designed props on Burkes, and that, have much longer lives, but yes, it won't occur in a CMO scenario...

...not even one designed by me!

_____________________________

"Some people spend an entire lifetime wondering if they made a difference. The Marines don't have that problem."
PRESIDENT RONALD REAGAN, 1985

I was Navy, but Assigned TAD to the 24th MAU Hq in Beirut. By far the finest period of my service!

(in reply to HalfLifeExpert)
Post #: 11
RE: Cavitation and Surface Vessels - 10/27/2020 3:22:15 AM   
magi

 

Posts: 1504
Joined: 2/1/2014
Status: offline

quote:

ORIGINAL: BeirutDude

We had to take the prop off the USS Iwo Jima (LPH-2) in Metro Shipyards, Portsmouth, VA and it looked very much like those pictures. During high speed runs (above 15 knots ) she would shake like a wet dog and in the aft portion of the ship you could feel the cavitation bubbles slap the blades! The other interesting part of that was the rudder pin needed to be replaced. They had to cut through three decks to get it out with a huge tripod crane and it was a huge Clevis Pin!

very interesting.......

(in reply to BeirutDude)
Post #: 12
RE: Cavitation and Surface Vessels - 10/27/2020 7:30:20 AM   
Parel803

 

Posts: 201
Joined: 10/10/2019
From: Netherlands
Status: online
Dear Wood, than I misread the first question and apologize for my interpetation of the english language.
with regards

(in reply to magi)
Post #: 13
Page:   [1]
All Forums >> [New Releases from Matrix Games] >> Command: Modern Operations series >> Cavitation and Surface Vessels Page: [1]
Jump to:





New Messages No New Messages
Hot Topic w/ New Messages Hot Topic w/o New Messages
Locked w/ New Messages Locked w/o New Messages
 Post New Thread
 Reply to Message
 Post New Poll
 Submit Vote
 Delete My Own Post
 Delete My Own Thread
 Rate Posts


Forum Software © ASPPlayground.NET Advanced Edition 2.4.5 ANSI

0.139