http://autoweek.com/apps/pbcs.dll/article?AID=/20060224/FREE/60222004/1024

The article is sketchy on details, but Mr. Crower is trying to eliminate the need for a radiator, and instead use that heat for productive work instead of wasting it. If I am reading it correctly, it would go: intake, compression, expansion, exhaust, direct injection of water which flashes to steam, steam expansion...and then repeat. It also keeps the exhaust valve cooler (they don't explain how), which means you can run higher compression, which also means more efficiency.

Very interesting. I see more potential in this than in BMW's steam system...

If BMW's steam engine has enough power to push a DeLorean up to 88mph, that's good enough for me!

While the BMW system does add performance and better gas mileage, it also adds weight. This systems looks like it can increase performance, give better gas mileage AND reduce weight. I'm all for that!

COOL, the water tank might be a problem along with the danger of a boiler...but this is very cool!

There is no boiler. Think of water injection on a larger scale.

Well the million-dollar question of course is: Could you design a rotary engine to take advantage of this concept (IF it works, Mr. Crower doesn't know yet for sure)? Turning some of the rotary's prodigous amounts of underhood heat into more power would be nice. Plus the steam would help with carbon deposits, wouldn't it?

It would take a completely different design though; you can't just swap out a cam like on piston engines. Someone on another forum claimed that Mr. Wankel worked out other rotary designs with more than 3 sides on a rotor, and that might work...but I never heard of that.

Oh and speaking of the BMW turbosteamer, I wonder what the exhaust temps are on the Crower prototype. I wonder if you could use it in conjunction with the turbosteamer.

would this be possible on a rotary engine? Some things to think about , lubrication, how would you inject water into a rotary if your injecting oil to lubricate seals? If you could somehow lubricate the seals in another way this could make the rotary way more efficient dont you think? Rotaries are known to produce a lot of heat so It would seem that you could cool them off with this form of water/steam better than the tipical water jackets...........hmmmnm....thinking

Well the million-dollar question of course is: Could you design a rotary engine to take advantage of this concept (IF it works, Mr. Crower doesn't know yet for sure)? Turning some of the rotary's prodigous amounts of underhood heat into more power would be nice. Plus the steam would help with carbon deposits, wouldn't it?

It would take a completely different design though; you can't just swap out a cam like on piston engines. Someone on another forum claimed that Mr. Wankel worked out other rotary designs with more than 3 sides on a rotor, and that might work...but I never heard of that.

Oh and speaking of the BMW turbosteamer, I wonder what the exhaust temps are on the Crower prototype. I wonder if you could use it in conjunction with the turbosteamer.


never even thought of that, you could use the steam purge system to power a turbo also maybe?

never even thought of that, you could use the steam purge system to power a turbo also maybe?

after the engine warms up to a decent temp, you could get rid of turbo lag with this theoretical setup

The steam is going out the tailpipe along with the exhaust, and you have a water tank alongside your gas tank, basically. You could still run a turbo but I don't see how it would lag any less than before.

Of course, the whole premise behind a turbo is to use otherwise wasted energy in the exhaust...but something like this or the turbosteamer would have less wasted energy in the first place.

This seems like a neat idea:
Crower_six_stroke cycle engine (http://en.wikipedia.org/wiki/Crower_six_stroke)
The question:
How would we do a rotary version of a 6 cycle engine?
:uhh:

It sounds like it might work, but the engine reliability would be complete shite. Fuel and steam generate pressure in different ways. As fuel combusts, the pressure quickly spikes and then comes down as the stroke reaches BDC. With the water, its going to build sowly and then spike towards the end as more water is converted to vapor. This is going to be going on across 4,6,8,12 cylinders. All these different forces acting in different ways... Can anyone say stress fracture? Personally I think the engine would clog up with sediments and minerals from the water within 10000 miles unless you were using ridiculously purified water.

Also the wiki sounds like it was written by Bruce Crower himself.

The real question is

Will it blend? (http://www.willitblend.com)

Sediment build up should be avoidable using distilled water. It seems to me that the way to implement it on a rotary would be to have every other rotor face see either combustion or steam. It seems to me that it should reduce the peak temperatures on the rotor housings and side housings, given a margin of error on mechanical stress. The downside I see is that it turns the waste heat into useful mechanical work, so our heaters wouldn't work very well; but our fuel consumption would be cut, possibly even in half. I'm not clear on how to avoid the system being a total loss cooling system, however.

It seems to me that the implementation of this system in a rotary should be similar to the Direct Injection that Mazda is developing for the 16X.

Having every other face of the rotor see alternate modes, first internal combustion and then on the next face of the rotor steam, and so on, should give the desired result. The peak temperatures for the rotors and housings should be kept down, which should do some nice things for forced induction applications.

My concerns are:
1. whether the pressure curve is compatible with our seals as they currently exist
2. this system seems to be a total loss cooling system, essentially transferring the weight from the radiator to the storage tank (wherever it might be)
3. what do we use for a heater?
4. don't we lose fuel tankage space in order to accommodate the water tank, if we don't position it where the radiator currently is?

very strange things afoot

http://www.rx8club.com/showthread.php?p=2925743#post2925743

very strange things afoot

http://www.rx8club.com/showthread.php?p=2925743#post2925743

Is there a provision in the board's software to allow merging obviously related topics? Both this one and the one noted above are talking about the 6-cycle engine concept, and particularly how it might be adapted to the rotary. I posted in both because I wasn't sure which one might be more likely to garner further discussion and was hoping for feedback on my questions/concerns by those more knowledgeable than myself.

Interesting, longpath. Much better approach than that mentioned above of adding additional lobes, which would garner some heat from the rotor but not really address the rotor housing differential heat. Your approach would also reduce the temperature differences around the rotor housing.

Merged.

From what I saw on the wiki, and knowing what we know about the rotary, I would say that recycling the water via a condenser would absolutely require a water/oil separator; but I don't have enough knowledge of these devices to know if they are thorough enough for this application.

The other thing that occurs to me is that technically the variant I suggested (alternating IC/steam on adjacent rotor faces) isn't a 6 cycle, although it is derivative.

Is there a provision in the board's software to allow merging obviously related topics? .

sure as stealth did:). i didnt at the time because i wanted others to see the strangeness of the same "brand new thing" topics 2 years apart.....

I missed the dates!

S

I missed the dates!

S

I'm afraid I did too :(

Why not run one rotor off gas, and another rotor off steam (using the exhaust from r1 as the intake)?

Why not run one rotor off gas, and another rotor off steam (using the exhaust from r1 as the intake)?

I'm not sure I follow you. Do you mean use the heat in the cooling jacket to boil water to make steam to run one rotor while the other runs internal combustion?

If so, my thoughts are just that I don't see that reducing the peak temperatures or reducing the temperature variation across the engine. What I was suggesting, by alternating, was to capture and use the waste heat immediately and allowing the combustion chamber to be free of hot spots, allowing higher pressure levels without detonation during the internal combustion cycles.

Technically, what I am suggesting is not, in fact, a 6 cycle engine. It's actually an alternating mode co-generating engine. Normally, co-generation is implemented by using the waste heat to fire an external boiler that feeds an external steam engine, so it's normally only implemented in situations where fuel consumption rates are so large and the engine bay space is large enough to allow it, such as in large maritime installations or in stationary power-plants. Using the alternating mode, cogeneration could be incorporated into the wankel at only a fairly modest space penalty.

Unfortunately, I don't see any way that our existing PCM could do the job, even with a piggyback controller, so building a working prototype would be a pain, and beyond my skills or assets (I don't have the workspace or cash flow to sink into such an R&D project).

Sediment build up should be avoidable using distilled water.

Distilled water takes a considerable amount of energy to produce.

Edit: oops, pwned by thread resurrection!

Distilled water takes a considerable amount of energy to produce.


....and also about the same price as gasoline.

So lets say you forget to fill up your water tank, will it survive an overheating?

So lets say you forget to fill up your water tank, will it survive an overheating?

If the water isn't recovered and recycled, then that would be a definite no. On the other hand, I do recall reading about a system that DARPA was developing to allow potable water to be extracted from vehicle exhaust to provide soldiers with a secondary source of drinking water. I don't know how far along that research has gotten; but if it's mature at this point, then I would suggest using that equipment or a variant of it to capture water vapour from the combustion phase and steam from the steam phase so that the even if the gear isn't much better than 50% efficient, it would still reclaim enough water to keep the engine running as long as there was fuel.

It might be best to have two water sources. One would be a tank of distilled water with an anti-freeze additive (perhaps a simple alcohol like ethanol) and the rest would come from recycling. Alternately, a bottle of the anti-freeze might be separately metered into the water supply to keep the freezing resistance constant (I'm assuming that the recycling system wouldn't reclaim the antifreeze as the catalytic convertor might oxidise the anti-freeze into CO2 and H2O).

I assume someone already said this, but it's not 6 cylinders, it is only one. Also it is 6 strokes or cycles 7 events. It would not work in our engines as we operate much like a 2 stroke and do not have the ability to "add" extra strokes.