Interesting.Tommy Cookers wrote:FWIW
the HCV of iso-octane (the stuff that is our 100 Octane reference fuel) is 48 MJ/kg
propane (which is in gasoline until they remove it because it's valuable) has an HCV of 50.3 MJ/kg
Is combustion speed less of an issue now that the engine speed is down or is it more of a reason to combat detonation? Since it's now also DI, perhaps different fuel will be used?Tommy Cookers wrote:48 MJ/kg has been available for about 80 years, it's the reference fuel that's compulsory for Octane rating of motor fuel
current F1 fuel is formulated for combustion speed as the highest priority, not heat content/kg
the 46 MJ/kg seems entirely credible for such a fuel
I think UCV is used by convention in efficiency determinations (not LCV)
Where are they claiming a turbine efficiency of more then 78% ??? I couldn't find it???WhiteBlue wrote:http://turbo.honeywell.com/our-technolo ... ochargers/pgfpro wrote:OK that makes me feel better about my engine models now.
I know for fact that turbo's today the ones the manufacturers sale are only at 78% max. IMO a lot of this is because today's turbo's have a target of 40% waste gated mass exhaust flow, quote from Borge Warner (When as much as 40% of the flow needs to pass through the wastegate at maximum power, a flow-optimized solution is needed...) So if they could utilize all the exhaust mass flow through the turbine I could see a large increase in efficiency.
http://turbo.honeywell.com/assets/pdfs/ ... tation.pdf
Honeywell have started to make turbines and compressors in that efficiency class.
TC, the fuel content in the end will make very little difference. If you have confirmation of the fuel content I'll adjust all figures accordingly. The 46 MJ/kg is just a number which happened to be used when this thread started. I'm happy enough to change it for good reasons. Is there a figure you have evidence for? If not I think it is simply my estimate and I have to make he pick.Tommy Cookers wrote:WB makes efficiency predictions for new engines without knowing the UCV of the fuel they are using
in insisting that 46 MJ/kg is the only game in town he is exaggerating their efficiency (if their fuel has higher UCV)
48 MJ/kg has been available for about 80 years, it's the reference fuel that's compulsory for Octane rating of motor fuel
current F1 fuel is formulated for combustion speed as the highest priority, not heat content/kg
the 46 MJ/kg seems entirely credible for such a fuel
I think UCV is used by convention in efficiency determinations (not LCV)
if so IMO Blanchimont's efficiency calculations are also optimistic
current road petrol/gasoline has around 5% bioethanol, this lowers the CV by about 2%
presumably F1 fuel will have little reduction in CV from its compulsory biofuel content
oil not alcohol ?
They do not do that explicitly because the turbos are for a different purpose. The design is for reduced inertia, not for extreme efficiency. But the type of rotors is known to reach 85% efficiency.pgfpro wrote:Where are they claiming a turbine efficiency of more then 78% ??? I couldn't find it???
Are you sure it will be used in F1 next year, or is this just a private theory of yours?Tommy Cookers wrote:Cyclopropane 49.65 MJ/kg
perhaps you would like to check this ?