Rotary Titus

Hey guys, I remember reading in popular mechanics or science a few months ago and there was this engineer in India that created a system of making grooves and scratches on the inside of a combustion camber (for piston engines, but I guess one can do the same on the sides of the rotors?). Basically he simplified the idea to the grooves then created much more turbulance to mix the fuel and air mixture which resulted in greatly enhanced mileage and power. Also the engines were able to idle at like a really low rpm (have to dig up magazine...) and apparently made power at a really low rpm as well and the sound the engines make were so distinct it gave the engine a nickname (once again... have to find the magazine again!). It was another one of those "if it's such a great idea then why doesn't big car manufacturers already make them like that" thing, but the guy had great deal of problem with funding, patenting and basically getting anyone to listen to him. I found it rather interesting.
Anyone else read that story???

wakeech

hmm.. nope, didn't read it.

i'd have to see more precisely what you're talking about. turbulators in or out of a combustion chamber won't make that big a difference, and what's good for low rpm is bad for high rpm nearly universally.

Richard Paul

iTrader: (5)

Ah yes the old scratch trick. Been done before (damn I'm old) years ago to promote wet flow. So it was claimed. Last time I saw it done they used a center punch to dimple the chamber. Thinking of all those chambers I spent hours with a Dumor polishing.

Not buying it. The turbulence and tumble you need is as the air enters the chamber. Remember that turbulance restricts flow. Besides it interups the flame front. Like wakeech said you loose on the top, all makes logic.

In 1929 Dusenberg had an 8 cld twin cam four valve supercharged engine. Just like I said this morning about the Merlin it's all been done before. All we have gained is from electronics. And look how it's holding us captive now. Can't break into their code. Damn things have turned on us. They're gonna take over, you'll see. They're modifying themselves slowly. I think those machines of mine talk to each other at night and plot against me. They are looking at me right now.

Ajax

Richard,
Did you know that Bic Pens are made totally by machines in a facility that is totally unmanned?! I mean, isn't that incredible? But who is to say that the bic pen making machines arent smarter than we think? Maybe every so often instead of making pens, they make knives... and wheels... and arms and legs and build miniature plastic knife wielding robots of doom!?! Who is to say!?!? I mean.. THEY'RE COMING!!

Did you know that they also used a rat brain to fly an F-22?
Here's the article: http://www.sciencedaily.com/releases...1022104658.htm

Rotary Titus

LOL yea I think the rotary was one of the steps in their evolutionary process to take over??
Ok just found the magazine again it's september isseu (OK it ISN'T a few months after all!) and here's the link! So yea I guess it's not just scratching the sides of the chamber but also reshaping it as well? ( guess we can't apply that part to rotaries?) http://www.popsci.com/popsci/futurec...9464-1,00.html

Richard Paul

iTrader: (5)

Is he BSing me?? But I can see a reason. The 500,000 he gets to play in his shop.

Did you know that the Mazak machining centers are used to make more machining ceners. The first shift is fully staffed, the second has about 3 to 5 employees. The third shift is unmaned. That's when they make the well planed out small changes like you theorized.
They know when they break a tool or get dull. Then they take off the whole magazine send it to the tool room and bring in a new one. All the tool specs are in the computer so the machine makes the adjustments.

Richard Paul

iTrader: (5)

Well with ports that size and that included angle there will be more turbulence then the law allows. Ditto what I said before.

What's the matter with me?? Quench is the name of the dame. That's why they invented the wedge chamber. Actually it was Kettering circa 1946. You see the very close non-contact between the piston and the head forces the mixture to squirt out towards the sparkplug. Now with hemi chambers this hard to do. But a not really round chamber can have some squish area. same goes for the 4 valve pent roof. It's in the shape. Notice the Cosworth chamber is kinda like rectangular.
And all the modern 4 valves are evolusions of the Cosi, if not clear robbery.

Note: Other fuels then gasoline may not need the squish. Like fuels that contain their own oxidizer (Nitro)

Rennwagen

Wouldn't the "scratching" affect the seal that the apex seal makes against the housing wall? Seems there would be no place for the, "scratches" on a rotary.

wakeech

you don't have to do it on the block, you could just modify the shape of the combustin chamber depression to get a similar effect (has been done).

AQA101

I seriously doubt that some scratches could improve a combustion system geometry that has probably taken decades of experience, hundreds of working hours and some expensive facilities to design ...

Genom

Welp, the article (and I remember reading this a while back, cool someone else did too) was pretty interesting at least. He also only tested on some dinky little car, so it would be interesting to see on something built after the 70's :D

Rennwagen

I see. But the combustion, "chamber" moves in the rotary (with the rotor). In a piston engine, the chamber never moves (it just gets smaller) and so I can see where you'd want to stir the stuff up. But in a rotary, the combusiton area moves around the housing with the rotor. Wouldn't that action stir stuff up as much as the scratches claim to?

wakeech

it's not just mixing, it's trying to enhance the density and homogeneity (well ok, that would be mixing) of the charge around the spark plug. the motion of the rotor inside the engine kinda has this effect, but isn't as pronouced as you might think.

direct injection would be the next big evolution in mazda's wankel design, so we can get a truly stratified charge in the combustion chamber and get some decent fuel economy.

Richard Paul

iTrader: (5)

wakeech, Do you think that you are going to get better atomization because of the nozzel or because of the heat?/ The drops coming out of aa nozzel are not fine drops. they are to the eye but in chemistry terms the are large. Now heat will make it boil but pressure delays it.
Actually I don't know what the hell I'm talking about. It's 4:30 in the morning here and Need some sleep. Last thing I should do is press the Post button. I will anyway.

globi

Engine manufacturers were using techniques to create more turbulence in the combustion chambers: I think Honda came up with a concept that would lift one intake valve before another and therefore give the incoming air a twist to improve the air fuel mixing process. (Of course this only works with an engine with two intake valves.)
Also decades ago Saurer (a truck manufacturer) made intake valves with wings to swirl the incoming air.

However scratches only work on the surface (they might stir up the boundary layer) so I really don't see the benefit of that. After all its wings that make aircrafts fly not scratches. Or should I scratch the bowl before I mix the pancake dough in order to improve the mixing process?

globi

Actually there are simple universal air swirlers, that have been around for over 20 years:
http://www.turbonator.com/
http://www.spiralmax.com
http://auto.272.com/272/tfs.php?PHPS...e6c00676086f29

They all have one thing in common: They don't work.
http://www.ftc.gov/bcp/conline/pubs/autos/gasave.htm
What is fascinating though is that some of them are actually patented.

Maybe grooves (not scratches) in the combustion chamber on cars with side valves might make a difference. I wouldn't claim that the Indian guy in that popsci article is completly dishonest.