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Re: Honda Power Unit
Posted: 24 Feb 2018, 09:25
by etusch
Smaller sidepod inlets make me think that engines will run lesser power and because of this they need lesser cooling and more heat during race. If so Honda automatically catch rivals (if they didn't do same)
Re: Honda Power Unit
Posted: 24 Feb 2018, 10:50
by DFX
etusch wrote: ↑24 Feb 2018, 09:25
Smaller sidepod inlets make me think that engines will run lesser power and because of this they need lesser cooling and more heat during race. If so Honda automatically catch rivals (if they didn't do same)
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
Re: Honda Power Unit
Posted: 24 Feb 2018, 11:32
by techman
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
mercedes will disagree. the merc is the most efficient achiveing 50 percent thermal efficiency. and they have the biggest air intakes
Re: Honda Power Unit
Posted: 24 Feb 2018, 18:46
by DFX
techman wrote: ↑24 Feb 2018, 11:32
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
mercedes will disagree. the merc is the most efficient achiveing 50 percent thermal efficiency. and they have the biggest air intakes
They can disagree whatever they want, this is thermodynamics.
Re: Honda Power Unit
Posted: 24 Feb 2018, 22:20
by PlatinumZealot
That is true.
Other factors are internal aerodynamics, radiator efriciency, desired intercooling temperatures, ERS cooling and gearbox cooling
Re: Honda Power Unit
Posted: 24 Feb 2018, 22:32
by j.yank
DFX wrote: ↑24 Feb 2018, 10:50
etusch wrote: ↑24 Feb 2018, 09:25
Smaller sidepod inlets make me think that engines will run lesser power and because of this they need lesser cooling and more heat during race. If so Honda automatically catch rivals (if they didn't do same)
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
Actually he doesn't speak about efficiency but about saving power because of the 3 engines per season rule.
Re: Honda Power Unit
Posted: 24 Feb 2018, 22:41
by amho
DFX wrote: ↑24 Feb 2018, 10:50
etusch wrote: ↑24 Feb 2018, 09:25
Smaller sidepod inlets make me think that engines will run lesser power and because of this they need lesser cooling and more heat during race. If so Honda automatically catch rivals (if they didn't do same)
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
it's not neccessarily true. here fuel efficiency rules, imagine situations as follow:
engine A extracts 5000 kj from m(g) fuel and it has thermal efficiency of 0.6.
engine B extracts 1000 kj from the same m(gr) fuel and has thermal efficiency of 0.5.
heat rejection in engine A is 2000 kj and heat rejection in engine B is equal to 500 kj.
work (power) in engine A is 3000 kj and in engine B is 500 kj.
so u can see that engine A while has a higher fuel efficiency & power it also rejects more heat.(engine A has a better combustion efficiency).
https://drive.google.com/open?id=12ycBt ... pZKd_hbSsL
Re: Honda Power Unit
Posted: 24 Feb 2018, 22:53
by 63l8qrrfy6
amho wrote: ↑24 Feb 2018, 22:41
DFX wrote: ↑24 Feb 2018, 10:50
etusch wrote: ↑24 Feb 2018, 09:25
Smaller sidepod inlets make me think that engines will run lesser power and because of this they need lesser cooling and more heat during race. If so Honda automatically catch rivals (if they didn't do same)
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
it's not neccessarily true. here fuel efficiency rules, imagine situations as follow:
engine A extracts 5000 kj from m(g) fuel and it has thermal efficiency of 0.6.
engine B extracts 1000 kj from the same m(gr) fuel and has thermal efficiency of 0.5.
heat rejection in engine A is 2000 kj and heat rejection in engine B is equal to 500 kj.
work (power) in engine A is 3000 kj and in engine B is 500 kj.
so u can see that engine A while has a higher fuel efficiency & power it also rejects more heat.(engine A has a better combustion efficiency).
https://drive.google.com/open?id=12ycBt ... pZKd_hbSsL
Uhm thermal efficiency is work divided by energy available in fuel rather than heat extracted in combustion.
Re: Honda Power Unit
Posted: 24 Feb 2018, 23:03
by amho
Mudflap wrote: ↑24 Feb 2018, 22:53
amho wrote: ↑24 Feb 2018, 22:41
DFX wrote: ↑24 Feb 2018, 10:50
Completely the opposite. Less effient engines needs more cooling than higher effient ones.
it's not neccessarily true. here fuel efficiency rules, imagine situations as follow:
engine A extracts 5000 kj from m(g) fuel and it has thermal efficiency of 0.6.
engine B extracts 1000 kj from the same m(gr) fuel and has thermal efficiency of 0.5.
heat rejection in engine A is 2000 kj and heat rejection in engine B is equal to 500 kj.
work (power) in engine A is 3000 kj and in engine B is 500 kj.
so u can see that engine A while has a higher fuel efficiency & power it also rejects more heat.(engine A has a better combustion efficiency).
https://drive.google.com/open?id=12ycBt ... pZKd_hbSsL
Uhm thermal efficiency is work divided by energy available in fuel rather than heat extracted in combustion.
check it: (
http://energyeducation.ca/encyclopedia/ ... efficiency)
Re: Honda Power Unit
Posted: 24 Feb 2018, 23:08
by 63l8qrrfy6
amho wrote: ↑24 Feb 2018, 23:03
Mudflap wrote: ↑24 Feb 2018, 22:53
amho wrote: ↑24 Feb 2018, 22:41
it's not neccessarily true. here fuel efficiency rules, imagine situations as follow:
engine A extracts 5000 kj from m(g) fuel and it has thermal efficiency of 0.6.
engine B extracts 1000 kj from the same m(gr) fuel and has thermal efficiency of 0.5.
heat rejection in engine A is 2000 kj and heat rejection in engine B is equal to 500 kj.
work (power) in engine A is 3000 kj and in engine B is 500 kj.
so u can see that engine A while has a higher fuel efficiency & power it also rejects more heat.(engine A has a better combustion efficiency).
https://drive.google.com/open?id=12ycBt ... pZKd_hbSsL
Uhm thermal efficiency is work divided by energy available in fuel rather than heat extracted in combustion.
check it: (
http://energyeducation.ca/encyclopedia/ ... efficiency)
yes Qh is the fuel heating value times fuel mass. It is identical for both engines in your example. Since the first engine extracts 6 times more work from the same quantity of fuel your efficiency numbers can't be right.
Re: Honda Power Unit
Posted: 24 Feb 2018, 23:59
by amho
Mudflap wrote: ↑24 Feb 2018, 23:08
yes Qh is the fuel heating value times fuel mass. It is identical for both engines in your example. Since the first engine extracts 6 times more work from the same quantity of fuel your efficiency numbers can't be right.
Yes these numbers are too imaginary but I wanted to indicate that having higher thermal efficiency does not neccessarily means less heat ejection. Consider Qh for engine A & B equal to 700 and 500 kj for a given fuel and thermal efficiency of 0.5 and 0.4 respectively then A dumps 350 kj and B does 300 kj. Here in F1 if consider all engine have near the same combustion eff. then the one has better thermal efficiency it dumps less heat.
Re: Honda Power Unit
Posted: 25 Feb 2018, 00:11
by Tommy Cookers
well I've drawn back many times from saying this ........
thermal efficiency is not another name for overall efficiency of a heat engine
(we don't need telling that a heat engines job is to turn heat into work)
thermal efficiency is the efficiency of transformation of heat into work in the combustion chamber and not beyond it
(which too many wrongly insist on calling combustion efficiency)
but to allow harmony and understanding to flow .....
thermal efficiency can reasonably be called indicated thermal efficiency
and overall efficiency can reasonably be called brake thermal efficiency
simple !
Re: Honda Power Unit
Posted: 25 Feb 2018, 00:13
by 63l8qrrfy6
amho wrote: ↑24 Feb 2018, 23:59
Mudflap wrote: ↑24 Feb 2018, 23:08
yes Qh is the fuel heating value times fuel mass. It is identical for both engines in your example. Since the first engine extracts 6 times more work from the same quantity of fuel your efficiency numbers can't be right.
Yes these numbers are too imaginary but I wanted to indicate that having higher thermal efficiency does not neccessarily means less heat ejection. Consider Qh for engine A & B equal to 700 and 500 kj for a given fuel and thermal efficiency of 0.5 and 0.4 respectively then A dumps 350 kj and B does 300 kj. Here in F1 if consider all engine have near the same combustion eff. then the one has better thermal efficiency it dumps less heat.
Not imaginary, they were objectively wrong.
Since we are debating F1 engines what is the point of comparing engines of different fuels or different flow rates ?
DFX's statement was spot on.
Re: Honda Power Unit
Posted: 25 Feb 2018, 00:19
by amho
Mudflap wrote: ↑25 Feb 2018, 00:13
amho wrote: ↑24 Feb 2018, 23:59
Mudflap wrote: ↑24 Feb 2018, 23:08
yes Qh is the fuel heating value times fuel mass. It is identical for both engines in your example. Since the first engine extracts 6 times more work from the same quantity of fuel your efficiency numbers can't be right.
Yes these numbers are too imaginary but I wanted to indicate that having higher thermal efficiency does not neccessarily means less heat ejection. Consider Qh for engine A & B equal to 700 and 500 kj for a given fuel and thermal efficiency of 0.5 and 0.4 respectively then A dumps 350 kj and B does 300 kj. Here in F1 if consider all engine have near the same combustion eff. then the one has better thermal efficiency it dumps less heat.
Not imaginary, they were objectively wrong.
Since we are debating F1 engines what is the point of comparing engines of different fuels or different flow rates ?
DFX's statement was spot on.
I don't want to elongate chat but I didn't say anything about different fuel and flow, read once again carefully. Bye
Re: Honda Power Unit
Posted: 25 Feb 2018, 00:24
by PlatinumZealot
Tommy Cookers wrote: ↑25 Feb 2018, 00:11
well I've drawn back many times from saying this ........
thermal efficiency is not another name for overall efficiency of a heat engine
(we don't need telling that a heat engines job is to turn heat into work)
thermal efficiency is the efficiency of transformation of heat into work in the combustion chamber and not beyond it
(which too many wrongly insist on calling combustion efficiency)
but to allow harmony and understanding to flow .....
thermal efficiency can reasonably be called indicated thermal efficiency
and overall efficiency can reasonably be called brake thermal efficiency
simple !
Which one is the one car makers like to advertise though? Brake thermal or indicated?