Hybrid or Photo Detonation Vehicle September 2004

A Non-Registered Visitor writes "Quasiturbine - Hybrid or photo-detonation vehicle
? by Gilles Saint-Hilaire, Quasiturbine
Agence Inc.

Hybrid series versus parallel ?
Hybrid or photo-detonation vehicle ?
Good questions, because the parallel hybrids
are far more complex than the series one...
But parallel hybrids have been selected
because powers of the two hybrid units add-up,
which is the great advantage.
Series hybrids would required each unit
to have full needed power, because power do not add-up.
However, the selected parallel hybrid
do not permit an efficient "all electrical vehicle",
while the series hybrid does, and for this reason,
the series hybrid should wins later in the future...
.... If hybrid is need at all ?

Here about the "Raison d'être" of the hybrid concept :
Hybrid concepts are of interest and justified only to harvest
the energy lost when a high power engine run at low power.
Otto piston engines in transportation
have a load factor of about 15%,
which mean that the 200 HP engine
is most of the time producing about 30 HP !
My using a 30 HP engine at full power,
the potential fuel saving is of about 50%.
Hybrid system are not perfect,
so that about only half of that is recuperated in hybrid car.
Hybrid saving potential is then about 25% overall.
It is interesting, but not the panacea.

In doing an honest analysis the propulsion train physics,
one has to considere the possibility of a powerful engine
which would not have such a lost of efficiency when runing at low power.
In theory, this engine is possible with photo-detonation mode,
because then,
there is no need for the intake vacuum of Otto engine,
needed to produce a nearly stochiometric mixture.
Maintening this intake vacuum
is consuming a lot of energy at low power.
Attempt to make photo-détonation engine
has been made without succes with piston engines,
but sinewave crankshaft mouvement
is inappropriate for this mode as we have shown.
Quasiturbine (AC) has no crankshaft,
and pressure tip is 15 to 30 time shorter,
limiting the pressure stress and chemistry of the NOx...
However, there woud be no interest to make
an hybrid using a photo-détonation Quasiturbine,
because there will be so little penalty to low power operation...
à 200 HP QT could run at 20 HP with nearly the same
efficiency as a full power 20 HP engine.
There is no need for hybrid in this cir$%&*#@stances...

As the compression ratio goes up in machine design,
there are successively :
- deflagration (Otto heat wave front combustion),
- autolit (hot spot triggering still deflagration),
- Thermolit (a very irrégular process
where several little pocket of mixture lit spontaneously,
but where inter-region goes déflagration),
- and photo-détonation (there the compression temperature
is high enough to generate a high concentration of
black boddy radiation increasing as the power 4 of the temperature).
Notice that photo-détonation mode like Otto mode
compresses a fuel-air mixture,
while the diesel mode compresses only air.
However, Otto is near stochiometric combustion,
while photo-detonation is in abundant air excess mode...

Reference to powerful laser light is a good way to see it.
An otherway is to remember burning a paper
at the sun a focal point of a len.
Because piston does not stand the violent detonation,
gas contains anti-detonation additives,
which essentially act as photon radiation absorbants.
The Quasiturbine photo-détonation compabitilité
comes form the fact that the pressure tip is 15 to 30 time shorter,
which means autosynchronization and much less mechanical stress.
Furthermore, hability of the Quasiturbine to extract
precoce (early) mechanical energy is most favorable.
Of course, this will be the end of anti-detonation additives !
Knocking and pinging is a manifestation
of partial and non homogenious photo-détonation
for which the sinewave mouvement of the piston
is far to slow at perssure tip to properly synchronized
and manage the violent radiative volumetric combustion.

Photo-détonation is explained at :
http://quasiturbine.promci.qc.ca/QTPhotodetonation.html
HCCI process with piston engine is not quite a pure photo-détonation,
because in order to control somewhat the timing
and the stress, the intake is contaminated with exhaust...
which of course make some people conclude
that HCCI is not a pollution free combustion...
while pure photo-détonation can be !
- You may like to read Laurence Livermore Laboratory :
http://www.llnl.gov/str/Westbrook.html
- Scientific American, June 2001 :
A Low-Pollution Engine Solution -
New sparkless-ignition automotive engines gear up
to meet the challenge of cleaner combustion".
and have a look at :
- http://www.vok.lth.se/CE/research/HCCI/i_HCCI_uk.html
- http://www.cartech.doe.gov/research/emissions/HCCI-data.html
- http://www.me.berkeley.edu/cal/HCCI

There is a page describing the fundamental differences
between the Quasiturbine and the Wankel at :
http://quasiturbine.promci.qc.ca/QTpasWankel.html
It does required however a careful attentive reading to get it right...
Wankel DKM, KKM, and the piston,
all rely on sinusoidale crankshaft mouvement,
and as such, they are all photo-détonation incompatible...

About Hybrid, here is a statement from the
Quasiturbine www.quasiturbine.com researchers team :
Hybrid statement from the Press Release : ... Questioned about the Toyota
Hybrid System www.toyota.com and the PAICE Hyperdrive System www.paice.com , the president of Quasiturbine Agence Inc., Dr. Gilles Saint-Hilaire explained that " These are viable approaches for the near term because they are some of the best practical ways to avoid the
low-power-efficiency-penalty of the today high power vehicle engine, used with only 15% average load factor. But getting extra efficiency this way requires additional power components and energy storage, with associated counter-productive increases in weight, space, maintenance, cost and environmental recycling process". However, in addition to the Otto internal combustion mode Quasiturbine www.quasiturbine.com , Saint-Hilaire expects a rapid development of the photo-detonation Quasiturbine in the next 5 years, taking full advantage of its unique short and fast linear ramp pressure pulsed properties (This "knocking" mode is almost impossible for the sinusoidal crankshaft piston engine to tolerate). Such a photo-detonation Quasiturbine, notes Saint-Hilaire, "would have very little low-power-efficiency-penalty, would be more environment friendly as it would require low octane additive-free gasoline or diesel fuel, would be multi-fuel compatible, including direct hydrogen combustion, and would offer a drastic reduction in the overall propulsion system weight, size, maintenance and cost". This would tend to make the hybrid concept much less attractive long term, until such time when fully electric vehicles will efficiently "fuel" from the electrical grid." ...
See the complete Press Release at :
http://quasiturbine.promci.qc.ca/Presse/QTEmotionPR031217.pdf

Merci de vous intéresser au sujet...

Gilles
www.quasiturbine.com
*************************
"