Has anyone heard about pistons with cooling channels machined inside
them?? I recently came across such kinds of pistons that are used in
big marine engines. Can someone tell me the approximate stroke and
bore of these pistons?? what will be the typical size of a connecting
rod used in marine engines??
Thank you

Rahul wrote:
Has anyone heard about pistons with cooling channels machined inside
them?? I recently came across such kinds of pistons that are used in
big marine engines. Can someone tell me the approximate stroke and
bore of these pistons?? what will be the typical size of a connecting
rod used in marine engines??
Thank you


http://people.bath.ac.uk/ccsshb/12cyl/



--
“TAANSTAFL”

__________________________________________________ __________________________

"A prudent man foresees the difficulties ahead and prepares for them;
The simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
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Rahul,

A great number of real engines (bore6'[150mm]) have cooling features
under the piston crown, even some small truck engines have them. Few
are machined, but many are cast of forged that way.

If you are looking for the engines that actually circulate coolant
inside that piston, that is only common in crosshead design engines that
have a separate piston rod that is attached to a crosshead bearing and
that is attached to the connecting rod to the crankshaft.

This type of engine is common in the 1m bore class engines. I have seen
it as small as 600mm bore class. These engines have a coolant feed to
the crosshead and then coolant is piped up the piston rod to the piston
and returned to the crosshead.

Try some searching on Sulzer and Burmeister&Wain. They both build
engines this size and type.

Matt Colie


Rahul wrote:
Has anyone heard about pistons with cooling channels machined inside
them?? I recently came across such kinds of pistons that are used in
big marine engines. Can someone tell me the approximate stroke and
bore of these pistons?? what will be the typical size of a connecting
rod used in marine engines??
Thank you

On Apr 23, 12:23 am, Matt Colie wrote:
Rahul,

A great number of real engines (bore6'[150mm]) have cooling features
under the piston crown, even some small truck engines have them. Few
are machined, but many are cast of forged that way.

If you are looking for the engines that actually circulate coolant
inside that piston, that is only common in crosshead design engines that
have a separate piston rod that is attached to a crosshead bearing and
that is attached to the connecting rod to the crankshaft.

This type of engine is common in the 1m bore class engines. I have seen
it as small as 600mm bore class. These engines have a coolant feed to
the crosshead and then coolant is piped up the piston rod to the piston
and returned to the crosshead.

Try some searching on Sulzer and Burmeister&Wain. They both build
engines this size and type.

Matt Colie



Rahul wrote:
Has anyone heard about pistons with cooling channels machined inside
them?? I recently came across such kinds of pistons that are used in
big marine engines. Can someone tell me the approximate stroke and
bore of these pistons?? what will be the typical size of a connecting
rod used in marine engines??
Thank you- Hide quoted text -

- Show quoted text -

dazed and confuzzed - thank you for your reference to the world's
biggest diesel engine. I have actually seen it one year ago, but
forgot that it had piston cooling

Matt colie - Your information is really valuable and i got more info
by searching for sulzer pistons.. You have really helped me a lot for
my project.. As I am doing a heat transfer analysis on pistons, i
needed these information about the piston stroke, bore and the cooling
channel dimensions..

What can be the approximate values for the following?

Bore - 60cm??
Stroke - 90cm??
Engine rpm - 100
cooling channel dia - 1cm??
Inlet velocity of water or oil - 1m/s??
Piston crown temperature - 500 K??

As of now, I have modeled a 3d cooling channel which has an
inlet(vertical) at one extreme extending onto the piston crown, taking
a semicircular path around the underneath of the crown(horizontal) and
an outlet(parallel to the inlet) at the other extreme.. Is this
atleast remotely realistic??

Rahul,

I am afraid I have to let you down here. I have never seen the interior
layout of the piston cooling passages.

The only few things I can tell you for fact at this time is that Stroke
is approximately bore * 2 the (B&W K98 are 2.0m)

The K98 engine is published to run at 100rev/min and ~6000kw per cylinder.

If you can get to an engineering library, look up the
Diesel and Gas Turbine Catalog.
It should give you contacts and Sulzer and B&W (what ever they are
called today). You can probably get some information there.
As a student marine engineer, I was give a very nice tour of the
facility in Kobenhavn.

Best of luck
Matt Colie


Matt colie - Your information is really valuable and i got more info
by searching for sulzer pistons.. You have really helped me a lot for
my project.. As I am doing a heat transfer analysis on pistons, i
needed these information about the piston stroke, bore and the cooling
channel dimensions..

What can be the approximate values for the following?

Bore - 60cm??
Stroke - 90cm??
Engine rpm - 100
cooling channel dia - 1cm??
Inlet velocity of water or oil - 1m/s??
Piston crown temperature - 500 K??

As of now, I have modeled a 3d cooling channel which has an
inlet(vertical) at one extreme extending onto the piston crown, taking
a semicircular path around the underneath of the crown(horizontal) and
an outlet(parallel to the inlet) at the other extreme.. Is this
atleast remotely realistic??

On Apr 23, 6:48 am, Matt Colie wrote:
Rahul,

I am afraid I have to let you down here. I have never seen the interior
layout of the piston cooling passages.

The only few things I can tell you for fact at this time is that Stroke
is approximately bore * 2 the (B&W K98 are 2.0m)

The K98 engine is published to run at 100rev/min and ~6000kw per cylinder.

If you can get to an engineering library, look up the
Diesel and Gas Turbine Catalog.
It should give you contacts and Sulzer and B&W (what ever they are
called today). You can probably get some information there.
As a student marine engineer, I was give a very nice tour of the
facility in Kobenhavn.

Best of luck
Matt Colie





Matt colie - Your information is really valuable and i got more info
by searching for sulzer pistons.. You have really helped me a lot for
my project.. As I am doing a heat transfer analysis on pistons, i
needed these information about the piston stroke, bore and the cooling
channel dimensions..

What can be the approximate values for the following?

Bore - 60cm??
Stroke - 90cm??
Engine rpm - 100
cooling channel dia - 1cm??
Inlet velocity of water or oil - 1m/s??
Piston crown temperature - 500 K??

As of now, I have modeled a 3d cooling channel which has an
inlet(vertical) at one extreme extending onto the piston crown, taking
a semicircular path around the underneath of the crown(horizontal) and
an outlet(parallel to the inlet) at the other extreme.. Is this
atleast remotely realistic??- Hide quoted text -

- Show quoted text -

I knew it was too much to ask you about these details.. I just had a
wild hope.. thats all.. If i had got this information a month back, i
would have enquired further into the dimensions of the piston(because
i'm nearing the deadline for my project) anyways.. Thank you for your
interest in my problem.. Thanks to google for making it so easy to get
information from across the world..

Hello Rahul,

What I would do:

1. Check the libraries of the technical universities in the Netherlands and
order the books/studies of my choice to be sent to the local library.
http://aleph.library.tudelft.nl/F/LJ...le_name=find-b
Not much new since I left school

2. Check the bookstores equivalent to Amazon and second hand markets online

3. Check the builders
http://www.wartsila.com/
http://www.manbw.com/
Contact these guys for information and ask them for access to their
technical manuals online for studying purposes.
They are hiring qualified staff at Wartsila in the Netherlands, so be eager
and willing.

4. There is some material around and the dimensions are fair enough to be
used and to be scaled in calculations.
When using this averaged data your calculations could be within 10% of
actual
http://www.wartsila.com/Wartsila/glo...g_rtflex50.pdf
The piston comprises a forged steel crown with a very short skirt. It has
combined jet-shaker oil cooling and is equipped with four rings of the same
thickness.
Calculated surface temperatures are all optimized for thermal strains in the
cover and piston crown...

Hope I could be of any help, my books and manuscripts are 35 years old and
the data of performance runs in former vessels will not do for your purpose,
its too general.


Groeten
www.4eggsco.nl

"Rahul" wrote in message
oups.com...
Has anyone heard about pistons with cooling channels machined inside
them?? I recently came across such kinds of pistons that are used in
big marine engines. Can someone tell me the approximate stroke and
bore of these pistons?? what will be the typical size of a connecting
rod used in marine engines??
Thank you