It is certainly recognised that cavitation is an important factor when
injecting diesel into the engine and the injectors are designed with
this in mind. The normal assumption is that it helps air/fuel mixing
but there may well be more to it than that.
I think the arguments that there are significant potential gradients
within cavitation bubbles as they collapse(e.g.
https://link.springer.com/article/10.1134/1.567892) are pretty
convincing, and the mechanism is essentially fluid independent, ie it is
not dependent on the polarised nature of water molecules. It would
therefore be present when cavitation bubbles in diesel collapse and may
well be a factor in igniting the diesel.
On 28/09/2017 18:41, JonesBeene wrote:
The history/science of efficient fuel combustion in the ICE is almost
completely understood, right? Any previously unknown gain in
efficiency would be a surprise. However, “cavitation” in the sense of
a mechanism for a net energy gain –is one feature/parameter which is
not well understood. Brian Ahern has been involved for years with a
technology of simply adding HV electrons to a diesel, which sounds
easy but in practice is not simple. Cavitation could improve that task.
In general when a gasoline powered ICE is converted from carburetion
to manifold fuel injection, there is a 2-3% efficiency gain. And if
converted to direct injection (GDI) like a diesel, then the efficiency
gain is closer to 5%, regardless of any change in compression ratio.
Therefore it is reasonable to suggest net gain is coming from the
higher pressure cavitation of the injector in GDI. This could be
optimized by even higher pressure injection (Mercedes has actually
patented this process). If increased cavitation were to be combined
with a source of HV electrons then the net gain could be forthcoming
beyond any expectations.
To backtrack, the higher efficiency of diesel engines is normally
considered to be related to increased compression ratio – and no doubt
most of it is. Diesel fuel has slightly more energy content but that
is negated by higher unburnt particulates. Higher compression ratio is
the biggest contributor to diesel efficiency, but we need to ask: is
cavitation responsible for any of the diesel efficiency gain? If so,
can this finding be used with gasoline too? Can direct injection be
used to add electrical charge (at the injector)?
In principle, it seems likely that cavitation bubbles would be an
easier way to channel electrical charge into an engine since bubbles
would protect against grounding. CES apparently demonstrate that ions
are gainful, even with no net polarity imbalance, and their work may
have implications for hydrocarbons. Given new findings about
cavitation in general, it is possible that a part of the extra
efficiency of the diesel configuration relates to cavitation, even
using the standard diesel. This could be optimized for the GDI
configuration (gasoline direct injection) once it is better
understood. Moreover, since the cavitation route itself has been
previously unrecognized as gainful in itself, there may be additional
ways to make it even better (assuming it is gainful on its own accord).
In cavitation and sonoluminescence the extra energy content is said
to relate to “bubble collapse” and shock waves - with the Casimir
effect possibly entering into the mix. Nigel has suggested LENR
possibly catalyzed by the neutrino flux. A “dense hydrogen” or hydrino
route is also possible and Casimir+UDH would be a hybrid suggestion.
This niche begs for more study since every 1% gain – when multiplied
by several hundred million vehicle driven daily is likely to be worth
about $10 billion to society yearly, not to mention less pollution.
Even this week, a News story exposes the fact that most SUVs and light
trucks are getting less than 20 mpg in the 2017 model year. That is
unacceptable and way too low - we have been lulled into thinking
gasoline will not surge in price soon, but it will.
Perhaps all of this will be made moot by the upcoming switch to
battery powered hybrids. That could take years.
We seem to be way too complacent in not providing better fuel economy
NOW, even if battery power arrives sooner than expected.