| Re: [GMCnet] Scuderi Split Cycle Engine [message #166309 is a reply to message #166217] |
Sat, 14 April 2012 08:12   |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
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Yesterday was a solid day of work. A rare thing these days and I have to make the most of any that come along.
I have a friend (he is still a friend) that has made a hobby of collecting information on different internal combustion engines. He has designs much like this in that collection. Some have even been built and used. Only those that were successful enough for some long term production are familiar to most people. I will not go of topic here in spite of the obvious temptation.
In thermodynamics, engines are defined by either their PV (pressure/volume) cycle or their TE (temperature/Enthalpy) cycle (that last one will take a long time to explain to a non-engineers, but it is the change in energy and the change in potential to store energy). There are many more designs of engines than most people are aware of. All but a very few in the current world fit into one of four simple categories. I will not describe the features of each because that would add more to this than I intend to write. Those four are Otto, Diesel, (both are actually very rare), Modified (Otto or Diesel - pretty much the same and what most are) and Rankin (turboshaft engines). These descriptions are used without regard to the hardware used to product the cycle.
I have only run a few true prototype engines in my career. I have seen as many more that were supposed to be operational. Even that few is more than one might expect when one considers the cost of building an operational prototype.
One of the things long understood about the 4-stroke Otto engine is that the efficiency is directly related to the expansion ration and the engine design makes the compression ratio the same as the expansion ratio. This is just one of the reason that little diesels do so well. Another unfortunate situation is that the compression side of the engine wants to be cooled as much as it can and the combustion side wants to be cooled only enough for the components to survive. Scuderi could get this right. So, there are two places that this design could win. The man speaking mentioned a charge air accumulator. This could be interesting as it could be used a clean air scavenging system. I would also like to know how they plan to control the power output of the SI version of the engine as there is no good place to throttle the airstream that would not hammer the thermal efficiency.
It is interesting that this design (except for the turbocharger pictured) could be done with no higher parts count or manufacturing precision than is in current production engines.
What I would have to do at this point is read the patent claims to understand what made this patentable. I will bet you that there is a prototype that has or will be tested in this town already, and that is just Detroit. The foreign manufactures watch developments and patents just as hard.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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