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Old 11-05-2010, 10:49 PM
W124 E300D W124 E300D is offline
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Join Date: Aug 2010
Location: UK
Posts: 331
Quote:
Originally Posted by layback40 View Post
W124.
That is a good report!!
Problem is that 99% of the members hear will not be able to follow the maths.
Probably 100% of those on the WVO forums would not be able to follow it either.
To any one with appropriate education in combustion/reaction kinetics it is relatively simple.
I've got a friend who works in pyro research, the have some test engine with tiny viewports and tons of sensors and use lasers to give live motion video of combustion events, eg they'll record 3 minutes of 1000 RPM, which means 1500 sequential ignition cycles, and then it gets number crunched by computers to create 3d models of the flame fronts.

these guys can measure tiny but intense shockwaves travelling through the combustion chamber (the speed of sound is much much faster at 500 psi...) and thanks to the lasers can do live spectrophotometry on the chemical compounds being created and destroyed, things that don't exist long enough to make it out the exhaust ports.

They also do full monitoring in the fuel injection systems themselves, eg inside the delivery pump and injectors. Both traditional and common rail high pressure with piezo injectors.

they have run all the veg oils (soy / rape / corn / coconut / etc) at one time or another and always come up with the same results, the extra double bonds in the veg oil totally alter the way it behaves as a fuel, and of course the veg oils are NOT hydrocarbons, because they contain oxygen bonded molecularly, which again screws up the chemical reactions.

they found the veg oils (unlike hydrocarbon dino diesel, which contains no oxygen, and is therefore sealed off from oxygen by the physical material of the injection system) were even reacting under the different conditions of high pressure inside the injection system, with microdiesling, carbon dumping and even (micro) spark erosion of the fuel itself.

The test runs on sardine oil produced so much "extraneous" crap that it actually damaged the test equipment in the injection equipment, not just the injection equipment, but the test equipment.
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