Tommy Cookers wrote: ↑
Sun Mar 19, 2017 1:17 am
glenntws wrote: ↑
Sat Mar 18, 2017 6:30 pm
......Because ethanol is such a short molecule and by it's own includes a oxygen atom for oxidation, we have a very low rate of unburned particles.
hasn't the oxygen atom already been used for oxidation ? - (if not then water is also useable as a fuel ?)
as a future fuel ethanol is viewable as conflicting with humankind's desire to grow food
bio isobutanol (produced virally/bacterially) seems to be better
(used as feedstock yielding specific energy competitive with gasoline's, so is surely being used as the F1 mandatory biofuel content ?)
ethanol (by distillation 95-96% pure but for fuel purposes is dehydrated to nominally 100%) ....here, interestingly .....
has about 5% more energy per unit air consumption than a good gasoline's
its evaporation causes 153 degF drop in temperature (gasoline's is 40 degF) at stoichiometric ratio, less of course when leaner
The production of Propane using genetically modified e-coli has now been achieved, being a gas it self extracts, currently low rate of production but give it a few more years development, the e-fuels industry is producing methane, hydrogen and now Propane all high energy density fuels. Managing the power into and out of Li-Ion cells is a complex issue so they don't flash over like a 8,000 hp drag engine, you have to manage the heat produced with their use and remove it as effectively as possible maintaining them at their most effective temperature of 20-25 Celsius, it's not easy unless you've got 5 Celsius ambient or an air conditioning system. Electric powertrains are not that easy, the energy and power density of the Energy Storage are a pita if you want small volume and mass like in a two wheeler, motorcycle or race car. You need Graphene super-capacitors to get the power density you want/need including enough cells to spread the load over to minimise heat production is going to require a prohibitively heavy and large energy storage, i've done the numbers!
The Island of Hockney after installing its own wind turbines to stop importing power from the UK Mainland is now producing Hydrogen and using this to power the Auxillary systems on the Ferries travelling to/from the mainland, charging electric cars even. Next Generation ferries will be Hydrogen fueled beasties. They even built a special light weight hydrogen transporter for their light weight roads.
Still think using Jet Assisted Compression Ignition is your best bet to reach 60% TE. Your surface to volume ratio isn't that great with lots of small cylinders using low bore to stroke ratio's, lots of surface to loose heat into is always going to reduce the TE even with TBC coatings on Piston crown and head fire surfaces, since your hybrid a large high BSR ratio cylinder would be better from a thermal losses point of view and with Ultra Lean Low Temperature Combustion you could use Steel Pistons, PistAl Racing in Italy produced these some years ago for the Ducati Testastretta 1198 cc V-Twin. Steel having a better thermal expansion to suit the TBC coating.
Smart control of the cylinder head cooling system, calculating the wall heat transfer from combustion and controlling electric 48 volt fans and pumps to remove only this heat, using sensors on in/out of engine/heat exchanger to verify would reduce parasitic losses and maintain liner and combustion surface temperature to maintain combustion stability and reduce emissions. A fast compute engine in engine management needed for these calculations, even simplified physics calculations these are cheap now, they even have Neural Compute Units in Arm/Mali CPU/GPU/NCU in the Kirin 970 and they consume little power, the 48 volt electrics more efficient again over 12 volt ones and wiring lighter.