The Steamboating Forum

Thank you very much for the responses so far. Fredrosse - I am especially interested in that home generation plant, as this is basically what I am trying to do. Or to clarify, I started designing the engine with such objective, before using it as my final project was suggested to me. I would be very grateful for the ASME paper. I have actually thought of making a quasi static analysis much like what you propose, and I will look into it. I had a talk with a professor today (who is overseeing my project) and he remarked that for designing the engine I should only look as far as the maximum flow speed with the valve open and not to let it exceed a certain arbitrary value, around 30 m/s. Flow analysis through the valves, I have been told, could be a thesis on its own. Having learned what I did recently I am inclined to agree. Yet I still want to include elements of it in. And perhaps I will look into the more detailed stuff after I finish this project, when time will be less pressing.

Bart - I have actually been following your project for some time now - therefore I am very happy that you provided this information. Thank you.

My main objective is to test certain arrangements, such as uniflow with condensation, uniflow with aux-exhaust (Skinner style), uniflow with tapping off some steam from expansion and counterflow with this engine. Giving it auxiliary exhaust valves should help accomplish this if their events are controlled differently for each case, except of course the counterflow arrangement which would necessitate them to be towards the front cover - this I want to avoid, and therefore to test the counterflow arrangement piston valves will be necessary, though of course a different set of valves and eccentric should be utilized for this. That is all in the future however - for now, the project or thesis is just to build this engine and have it behave predictably.

Back in the 1970s the USDOE spent millions on automotive steam systems, and published a report describing all of the power plants. As I recall about 4 automobiles were built, generally with monotube boilers and advanced high pressure engines. The major auto manufacturers participated, along with Lear and Besseler SES. I have lost my copy unfortunately.

I do recall however a lengthy discussion about having poppet admission valves, where steam cylinder pressure tends to unseat the valve, basically the opposite of IC engine practice. If compression pressures exceeded the main steam pressure, the admission poppet valve would act as a relief valve, dumping steam back into the admission chamber. This unintended mode of operation was stated to produce satisfactory operation, and was routinely allowed to occur when engine exhaust pressure was high enough to re-compress the residual steam in the cylinder to a pressure exceeding main steam pressure.

I'm curious about the disposition of this project

"addiator" are you still here on the steamboating forum? Any results or new information to share?