Turbulators and Valves?

[EvanH]

Not sure if it has ever been done. But I know on cars like an EVO, they have a turbulator strip on the top of the back window that helps supply air to the wing by making little vortexes of air.

I also know that when you are mixing gas and air you want the best possible atomized mixture for a good combustion.

So what about adding little fins, around the circumference of the valve face inside the head, where it wont cause clearance issues.

I would think that little vanes on the valve where the fuel/air pass over would be atomized more with little to no restriction.

[DocWalt]

The vortex generator on the Evo wouldn't help a whole lot on our cars, the airflow is pretty smooth over the rear window anyway. The Active Aero on VR-4's already completely neutralizes lift at around 90mph.

[EvanH]

I am talking about the concept of putting those vanes on the valve in the heads. Not our cars rear window.

[92RT-TT]

That thought scares me. All I picture is one of those vanes breaking off with age/abuse/wear and then you've got yourself a nice little chunk of metal in your cylinder.

[EvanH]

I dont think it would be that bad. Especially if you make the vanes and valve from one piece like a billet thing. Plus you make them right and they would last just fine. It would only be for the intake valves too.

[i3igpete]

i'm sure there's an SAE paper where someone tested this. search swirl and tumble analysis, i'll take a look as well.

my main concern is that there is no way to clock the valves and hold them in the same position. something that may work well at a given angle will work like crap if the valve is rotated slightly.

these may be of interest as some primary reading:
http://etd.ohiolink.edu/send-pdf.cgi/He%20Yuesheng.pdf?osu1190053207
www.jsme.or.jp/esd/COMODIA-Procs/Data/002/C90_P487.pdf

[DocWalt]

I am talking about the concept of putting those vanes on the valve in the heads. Not our cars rear window.

My bad, misunderstood you.

[EvanH]

I have never physically been able to study the passage way where the air flows over the valve. I would imagine it would have to be uniform in the passage way so as to flow evenly to begin with. Thinking about it something as short as an 1/8th of an inch could work if done up right. It woud have to. All edges in airflow produce a vortex. Even if it turns, if you have vanes all the way around the valve it should be fine?

Its ok Doc.

[i3igpete]

even if vanes go all the way around the valve, is that very minor differences to the port geometry can affect the flow. I mean even difference as small as 5 degrees.

the problem is that the net swirl torque from these mini-vanes is zero. the vortexes would (theoretically) all rotate inward towards the vane. the net effect is that the swirl coefficient is not changed (rotational momentum around the cylinder axis). It might actually hurt swirl if that has been designed into the intake port.

In any case, the vane vortices would be much much smaller than the large vortices created by the large bluff body of the valve head. consider the tumble vortex radius in figure 15a below. the vortices made by the vanes would be negligible - the vanes are too short to induce any spin.

http://www.google.com/url?sa=t&source=web&cd=13&ved=0CB0QFjACOAo&url=http%3A%2F%2Fwww.its.ac.id%2Fpersonal%2Ffiles% 2Fpub%2F1922-Semin%2520Sanuri-Nacses.pdf&rct=j&q=Characterization%20of%20Flow%20Produced%20by%20a %20High-Swirl%20Inlet%20Port&ei=IWmaTN3XNIP5nAeoo5mQDw&usg=AFQjCNELEEulGDwlGaLjWmw86u3-G7Fy9Q&sig2=3TWA3oD7ncVZaV7MCXRy3w&cad=rja