Hi Paul，

    The efficiency of internal combustion engines are not good as the
exhaust gas is hot,
    especially on rotary engines.  If we inject small amount of water
into the chamber
    just after ignition, and the water would evaporate and expand.
Would this improve
    efficiency?  The water would take heat from the gas, thus make
further use of the heat.
    I think this may increase gas mileage in cars significantly. How do
you think?

    Best regards,

    Gordon Gao

    Of course it would work but there are all sorts of issues. Like
rusting the end housings
    after you turn it off.  Two tanks to fill.  Water must be distilled.

    The six cycle engine does this. Google it.

    Paul Lamar

Some people are collecting water via condensation from the intercooler
to use as water injection.  If you had some amount of cooled EGR, that
would provide a lot of water to condense along with increasing the ratio
of specific heats to reduce the peak compression temperature and thus
heat transfer.  If Mazda goes with aluminum end housings, that would
reduce the tendency for rust.

Once you add EGR, your burn rates will slow down so an aggressive
ignition would be required such as Paul's capacitive discharge or SwRI's
DCO system.  If you wanted to further increase burn rates, a dedicated
EGR system could be employed which routes one exhaust straight to the
intake so that rotor can run pig rich (30% to 50% additional fuel beyond
stoichiometric) and make CO and H2, but that requires at least 4 rotors
to get EGR rates to 25%.  It may also be possible to induce charge
motion by having a tumble plate but then you trade VE for burn rate.

Aaron Buster

Hi!: exhaust  gas temperatures depends on several factors, one was effective
compression ratio, poor bmep, the lower CR, the hotter exhaust gas temperatures, in
RCE, an added element is flame propagation only in the direction of rotor turn,
this leaves a zone of unburned mix in the trailing side. Problem is inherent to Wankel.
I don't know more.
Thanks, regards, + Salud
Jose Gros-Aymerich
Madrid, Spain


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