Search found 23 matches
- Wed Nov 30, 2011 2:24 am
- Forum: Technical - Engines and Boilers
- Topic: Tverskoy-Pasechnik Rotary Steam Engine
- Replies: 14
- Views: 18388
Re: Tverskoy-Pasechnik Rotary Steam Engine
RogerV, the interlocking rotary engine you are referring to is indeed in interesting design. The original Tverskoy documentation actually states that it can also double as a pump. He designed it for battleship use. His thought was that you could have a set of these engines all attached to a single a...
- Sat Nov 05, 2011 2:22 am
- Forum: Technical - non Engines and Boilers
- Topic: Coefficient of linear thermal expansion
- Replies: 2
- Views: 6514
Coefficient of linear thermal expansion
My old physics textbook states that thermal expansion is is directly proportional to the change in temperature for relatively small changes in temperature (less than 100C˚ or so). It also hints that the coefficient depends somewhat on the temperature. It does not, however give any details of the non...
- Tue Nov 01, 2011 7:58 pm
- Forum: Technical - Engines and Boilers
- Topic: Mean Effective Pressure calculations
- Replies: 8
- Views: 11723
Re: Mean Effective Pressure calculations
AHA! There's the confirmation I was hoping for. I've juggled the equations a bit (updated the pdf: http://russkey.tumblr.com/post/12141995522/mep ) (and removed the illogical +P_b term in Eq. 5 and on) and came up with a formulation that only depends on the input pressure, back pressure, and the rat...
- Mon Oct 31, 2011 9:52 pm
- Forum: Technical - Engines and Boilers
- Topic: Mean Effective Pressure calculations
- Replies: 8
- Views: 11723
Re: Mean Effective Pressure calculations
I think the relationship you're using for expansion of steam is wrong for adiabatic expansion. Bart: You are correct. I'm assuming isothermal expansion, which is the relationship I've found in two books so far (at least for the initial rough estimates at the very theoretical level). fredrosse: This...
- Mon Oct 31, 2011 1:21 am
- Forum: Technical - Engines and Boilers
- Topic: Mean Effective Pressure calculations
- Replies: 8
- Views: 11723
Mean Effective Pressure calculations
Hello all,
I've put together this calculation of Mean Effective Pressure. I couldn't find this sort of estimation in the Steam Engine Design book by Lindsay Publications. I would love to get a second opinion on the math, though.
Any comments?
http://russkey.tumblr.com/post/12141995522/mep
I've put together this calculation of Mean Effective Pressure. I couldn't find this sort of estimation in the Steam Engine Design book by Lindsay Publications. I would love to get a second opinion on the math, though.
Any comments?
http://russkey.tumblr.com/post/12141995522/mep
- Fri Oct 21, 2011 2:52 pm
- Forum: Technical - Engines and Boilers
- Topic: Suitable Boiler for a LocoMobile Twin Simple (6hp)
- Replies: 23
- Views: 29048
Re: Suitable Boiler for a LocoMobile Twin Simple (6hp)
... how do you know what RPMs you should be turning ? ... Based on the things I've seen on this forum, as well as my reading of Steam-Engine Design, it seems that the only really practical way is to estimate and interpolate the RPM based on existing data on documented engines of similar configurati...
- Mon Oct 10, 2011 6:01 pm
- Forum: Technical - Engines and Boilers
- Topic: Tverskoy-Pasechnik Rotary Steam Engine
- Replies: 14
- Views: 18388
Re: Tverskoy-Pasechnik Rotary Steam Engine
Please forgive the possible blasphemy, but has anybody tried using a electronic valve timing mechanism? Something based on solenoid valves would be quite quick. A simple microcontroller would handle the input from a rotary encoder of some sort and the output to the valves. You could even use some of...
- Fri Oct 07, 2011 12:00 am
- Forum: Technical - Engines and Boilers
- Topic: steel cylinder?
- Replies: 23
- Views: 31796
Re: steel cylinder?
What kind of lighter and stronger materials do you have in mind? Perhaps not lighter and stronger, but easier to work with. I've always thought that cast iron was rather hard to machine due to some sort of crumbly nature. But perhaps that is just some silly thing I've picked up. Do the castings tha...
- Thu Oct 06, 2011 12:46 pm
- Forum: Technical - Engines and Boilers
- Topic: steel cylinder?
- Replies: 23
- Views: 31796
Re: steel cylinder?
This is actually something that has puzzled me for some time. Why *do* people still use cast iron? Why not lighter, stronger materials? Is it some sort of heat transfer concern?...I believe cast iron is the material for cylinders and always will be...
Al
- Tue Oct 04, 2011 2:11 am
- Forum: Technical - Engines and Boilers
- Topic: Tverskoy-Pasechnik Rotary Steam Engine
- Replies: 14
- Views: 18388
Re: Tverskoy-Pasechnik Rotary Steam Engine
I presume that there was a time when even 50 micron machining accuracy was not possible, engines had to make do with some sort of tolerances and gaps between the cylinder and piston. Are there guidelines for an acceptable measure of seal imperfection? I would imagine that it might depend on the pres...