3 ms·
Of all the pre-war cars I have been in or around... only steam had the power to throw you back in the seat. It would be interesting to see a modern multifuel in
by whenchamenia 7y ago
Of all the pre-war cars I have been in or around... only steam had the power to throw you back in the seat. It would be interesting to see a modern multifuel interpretation of one. Might be well suited to long runtimes and alternate fuels.
- mysterydip 7y agoNot exactly what you asked for, but have you seen BMW's turbosteamer concept? https://newatlas.com/go/4936/ https://newatlas.com/go/4936/
- deleted 7y ago[deleted]
- mikepurvis 7y agoHa, I remember reading about that in university. One of the options my group considered for a culminating project in our engineering degree was a 6-stroke rotary (Wankel) engine that would have a water injection phase after the exhaust was pressed out. I don't think manufacturing a working model of such a thing would have been within reach for a couple of undergrads, although the project we went with was almost as ambitious— we ended up building a mostly functional laundry washer from scratch.
- wukerplank 7y agoWoah! Never heard of it. > The long-term development goal is to have a system capable of volume production within ten years. I guess they canned the project?
- aidenn0 7y agoThe problem with steam is that external combustion tends to be very fuel inefficient compared to internal combustion. This is true in general, but becomes even more true when you constrain the size and weight of the engine.
- RobertRoberts 7y agoI am not sure it's less efficient by default or simply because of lack of R&D into making steam engines better. I read about a government program in maybe the 70s (oil crisis?) where steam engines were reviewed to replace gas engines. The reason being is that burning fuel at atmospheric pressure means you burn it more cleanly and fully. This sounds like an efficiency balance at some level, certainly a pollution advantage. A quick search brought up this: https://en.wikipedia.org/wiki/Advanced_steam_technology#Automotive_uses https://en.wikipedia.org/wiki/Advanced_steam_technology#Auto... https://www.damninteresting.com/the-last-great-steam-car/ https://www.damninteresting.com/the-last-great-steam-car/
- nostrademons 7y agoYou run into Carnot cycle [1] physical limits. The efficiency of any heat engine is bounded by 1 - Tc/Th, i.e. the ratio of the absolute temperatures of the cold reservoir (usually the exhaust gases) to the hot reservoir (combustion temperature). To make an engine more efficient, it needs to run as hot as possible. Non-superheated steam engines are bounded by the boiling point of water (373 C); assuming 21 C outside air, you get a max theoretical efficiency of about 22%. ICEs are typically bounded by the thermal limit of the cylinder material; for iron engines, this gives about 37% efficiency. Superheated steam or closed-cycle (eg. Stirling) engines can do a lot better than this - Stirling engines can reach 50% efficiency, and this is nearly matched by superheated steam engines as used in power plants. But then you run into weight & safety problems. Superheated steam is great in a nuclear reactor or battleship, but in a car where a crash could easily break the engine piping? You're turning survivable crashes into death traps. [1] https://en.wikipedia.org/wiki/Carnot_cycle https://en.wikipedia.org/wiki/Carnot_cycle
- tigershark 7y agoWater boiling temperature is 373 K, not Celsius. 21 C of the air temperature is 294 K.
- nostrademons 7y ago