Thanks for the reply.godlameroso wrote: ↑Wed Mar 14, 2018 7:21 pmAt high temperatures nitrogen dissociates with oxygen and can lead to formation of ammonia and if there's chlorine present can form hydrogen chlorides, or nitrogen tri-chloride. Telltale sign would be a green tinge to the combustion.
Could be possibly used to add extra energy to the turbine IF you could get it to work.3jawchuck wrote: ↑Wed Mar 14, 2018 7:40 pmThanks for the reply.godlameroso wrote: ↑Wed Mar 14, 2018 7:21 pmAt high temperatures nitrogen dissociates with oxygen and can lead to formation of ammonia and if there's chlorine present can form hydrogen chlorides, or nitrogen tri-chloride. Telltale sign would be a green tinge to the combustion.
Is this likely to be happening in these engines? Is there anything to be gained by this or would it just be a byproduct of the combustion method that is in use? Surely to gain anything from this there would have to be something added to the combustion?
Sorry for any dumb questions, but this is not at all my field
Could indicate the presence of hydrazines? Maybe banking on the formation of some hydrazine nitrate during the combustion process?
Depends, I suppose it could help if you treat it like seasoning instead of a marinade, so to speak.
Oh for sure, iirc the drag cars ran with around 2% hydrazine to whatever the base fuel was, not sure if they used nitro then or not, 5% could kill you if you got too many fumes. Not to mention it's penchant for detonating and blowing the whole car up!godlameroso wrote: ↑Wed Mar 14, 2018 8:42 pmDepends, I suppose it could help if you treat it like seasoning instead of a marinade, so to speak.
At a first glance it appears possible to estimate both drag and inertia with a similar method to what you suggest provided either of them is known. That was the reason I suggested it would be interesting to look at low speed full power data.gruntguru wrote: ↑Wed Mar 14, 2018 7:05 amUp-votes to Mudflap and Henry for quality effort.
It is theoretically possible to estimate drag losses from the acceleration data, since aero drag power loss is proportional to (approx) velocity cubed, while acceleration is proportional to whatever-power-remains, divided by velocity. So if there were no losses, the acceleration at 300 km/hr would be half the acceleration at 150 km/hr and the same engine power. If we introduce aerodynamic drag the acceleration at 300 will be less than half the acceleration 150 - how much less will depend on Cd.A.
Other complicating factors include inertia of rotating parts. Final drive and wheels simply increase the apparent mass of the car. Moving parts (including pistons, con-rods, valves etc) upstream of the gearbox will increase the apparent mass of the car by an amount which is larger (proportional to overall gear ratio squared) and dependent on the gear selected. So the car has more inertia in the lower gears.
johnny - when the car is traction limited, the acceleration is no different whether there is 500 hp available to spin the tyres or 5000 so this part of the acceleration profile cannot be used to calculate effective power.
Looks very interesting.Mudflap wrote: ↑Wed Mar 14, 2018 9:20 pmAt a first glance it appears possible to estimate both drag and inertia with a similar method to what you suggest provided either of them is known. That was the reason I suggested it would be interesting to look at low speed full power data.gruntguru wrote: ↑Wed Mar 14, 2018 7:05 amUp-votes to Mudflap and Henry for quality effort.
It is theoretically possible to estimate drag losses from the acceleration data, since aero drag power loss is proportional to (approx) velocity cubed, while acceleration is proportional to whatever-power-remains, divided by velocity. So if there were no losses, the acceleration at 300 km/hr would be half the acceleration at 150 km/hr and the same engine power. If we introduce aerodynamic drag the acceleration at 300 will be less than half the acceleration 150 - how much less will depend on Cd.A.
Other complicating factors include inertia of rotating parts. Final drive and wheels simply increase the apparent mass of the car. Moving parts (including pistons, con-rods, valves etc) upstream of the gearbox will increase the apparent mass of the car by an amount which is larger (proportional to overall gear ratio squared) and dependent on the gear selected. So the car has more inertia in the lower gears.
johnny - when the car is traction limited, the acceleration is no different whether there is 500 hp available to spin the tyres or 5000 so this part of the acceleration profile cannot be used to calculate effective power.
So for drag we can use a generic term for the constants f=rho*Cd*A. Choosing two points, one at peak power low speed, one at peak power high speed we can write v1(m*a1+f*v1^2)=v2(m*a2+f*v2^2) and re-arrange to get f=m*(v2*a2-v1*a1)/(v1^3-V2^3).
Similarly, to calculate inertia we can pick a low gear peak power point (which gives high driveline acceleration) and a high gear peak power point. The assumption here is that inertia does not vary with gear ratio (which it totally does, but I think not by much as a fraction of total lumped driveline inertia). Writing the power at both points as the sum of the power required to accelerate the car against drag (F*v) and the power required to accelerate the driveline (I*a*w) at a given speed we can write F1*v1+I*a1*w=F2*v2+I*a2*w and re-arrage to get I=(F2v2-F1v1)/(w*(a1-a2)). Here F is the sum of the inertial and drag loads, w is engine angular velocity and a is engine angular acceleration.
I might try to do a slow speed point (and also check the math) this weekend if I get the time and no one beats me to it.
What about high flame temperature and rapid combustion, but low convective transfer of flame temps due to air dilution. In other words the large air mass creates an insulative layer for the heat generated. So even though the sensors pick up low combustion temperatures in cylinder they may not correspond to the actual flame kinetics. Much like the thermosphere has high temperatures but low convection, however in that case it's from a lack of density, which is the opposite of what I imagine is happening here.Tommy Cookers wrote: ↑Wed Mar 14, 2018 11:19 pmsignificant NOx is produced (by burning monatomic nitrogen) only at high temperatures sustained for some millisec
only such conditions produce combustible monatomic nitrogen from atmospheric (non-combustible) diatomic nitrogen
11000 rpm running of a (heat dilution) F1 engine won't produce much NOx as in-cylinder temps & time will be low
the high boost used to give abnormally high AFR is what gives heat dilution ie abnormally low power stroke temperatures
these temperatures are even low enough to avoid (undesirable) dissociation in fuel carbon and hydrogen combustion reactions
operation to use nitrogen as free fuel would cost more energy via losing the efficiency of heat dilution than it would gain
Even if they use the maximum fueling permitted throughout the rpm range (and my gut feel is that is what they do, whenever they are not in conservation mode) you would still expect the power peak to be somewhere above 10,500. Common sense says the physical engine design parameters would be optimised for an engine speed somewhere in the middle of the range to be used - lets say 11,500. If they optimised for 10,500 the peak power would be higher but the band where power was better would only extend approximately from 10,500 to 11,000 - everywhere above that would be worse.Tommy Cookers wrote: ↑Wed Mar 14, 2018 12:24 pmas the cars have no CVT time spent between 10500 and 12000 ish rpm dominates race performance
fuelling eg at 95 kg/hr at 10500 and 100 kg/hr at 11500 is more efficient as AFR & boost are near optimal throughout
fuelling at 100 kg/hr at 10500 and 11500 does not allow optimal AFR & boost throughout
this might not apply at lower speeds ie ripping through the gears, when brief and small fuel accumulations are possible