Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[rathikrishna]

Good after noon all...can we use a axial steam engine, means a turbine instead of a piston assy,in our craft..?  will it work..?..any advice..please..i am willing to make a tow boat with such an engine...

[BarryM]

It will work and it has been done but because of the near impossibility of making an efficient turbine at our scales, it will require a large boiler to meet the steam demand of a small unit.

Regards,

Barry M

[gondolier88]

You would also need a large reduction gearbox if you are going to use it in a tug.

Greg

[pettyofficernick]

As well as a reduction gearbox, you will also need an efficient lubrication system for the bearings as steam turbines run at extremely high speeds 

[Martin (Admin)]

Also see:  http://www.modelboatmayhem.co.uk/forum/index.php?topic=6781.msg67261#msg67261

[rathikrishna]

Oh god...better use a motor...thank you all....

[tony52]

As a postscript to this thread, myhobbystore offer a simple turbine in one of their publications.
The turbine is not really suitable for marine use, more of an easy build model engineers project. The problem for marine use is the weight of the boiler for a vessel powered by a small size turbine.
Nevertheless for anyone wishing to build a turbine this item is excellent and the price of the publication is not going to 'break the bank'.

http://www.myhobbystore.co.uk/product/17875/building-simple-model-steam-engines-book-ii

Tony.

[rathikrishna]

Ohh..its great..thanks for the link Tony...have a nice day..

[bbjs]

Anything seems possible...
Here's a production unti for r/c:

http://jc-steam.com/estore/product_info.php?products_id=405




Seems quite small, working pressure 20-80 psi, 50-2800 rpm.

Cheers, Bjorn

[rathikrishna]

Ahh..its great..any how i will make one..now i am in my work home to build a paddle steamer...

[steamboatmodel]

Anything seems possible...
Here's a production unti for r/c:

http://jc-steam.com/estore/product_info.php?products_id=405




Seems quite small, working pressure 20-80 psi, 50-2800 rpm.

Cheers, Bjorn

They give a working pressure, but don't say what the steam consumption is, that is usually the killer with turbines
Regards,
Gerald.

[gondolier88]

A 15mm exhaust connection, when coupled to an 80psi inlet pressure, would be a HUGE steam consumption. However you would probably be able to couple this to a flash steam boiler that would not be too heavy for the amount of steam it would be able to make. I would PM Flashtwo as this is his area of expertise and would be able to advise the size of the boiler you would need.

Greg

[rathikrishna]

thanks for the opinions..once again..i am already contacted a lathe work, to make a reciprocating one with brass..i hope it will work..

[Circlip]

15mm exhaust connection is only to ensure the engine doesn't "Choke" 20 to 80 PSI on a 1.2 mm bore nozzle, although needing a plentifull supply of steam isn't overthirsty.

  Regards  Ian.

  Yes, we'll now wait for the reams of maths.

[ooyah/2]

rathikrisna.
I have a copy of an article posted in Marine Model International in May 2002. it's about a small turbine that powers a model of the TURBINIA. without the use of expensive machinery.
There are 5 pages and pictures so if you would like it P.M. me with your e-mail and I will scan it and send it to you.
George.

[flashtwo]

Hi,

Last September at the Blackheath club (Steamboatphil, Alan Rayman et al), I saw a static demonstration of a steam turbine powered boat supplied by a flash steam boiler.

It was fine piece of engineering with the turbine shaft not only powering the prop shaft, but also the feed water, lub oil and fuel pumps via a large reduction gearbox (49:1?).

The turbine sounded like a gas turbine running up and threw a great plume of water a good twenty feet (7 metres) out of the pond and onto the shore.

The boat is designed as the tethered variety (see On-the-wire website) and the turbine is required to run for as along as it takes to do the five timed laps for that type of boat.

One leason learnt by the builder, so far, is to allow for lots of thermal expansion in the engine due to the very high steam conditions from the flash boiler- too tight a tolerance results in the turbine seizing up.

There are no automatic control systems, so, currently, it is a challange to run the power plant for much more than twenty seconds (though I stand to be corrected on that).

My own current approach is to experiment with a flash boiler /jet engine (see the Steam Jet Engine thread) which has great potential and has extended runs of twenty minutes. Apart from the electric water pump, there are no moving parts and the flash boiler/engine has reached 300psi (20Bar) at 720degC steam conditions.

I am currently rebuilding parts the water pump out of more robust materials and replacing the brass (which tends to melt!) in the boiler/engine with steel.

Ian