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stoichiometric combustion ratio is 14.7:11lt weighs of petrol weighs 0.72kgSay car gives 12km/litre (~36 miles/UK gallon)- or 8.64km/kg of petrolIn fifth gear the car travels ~1.9km/min (70 miles an hour)0.22 kg of petrol consumed in a minuteSo 14.7 * 0.22 gives 3.23kg of oxygen needed per min.Have I messed up somewhere?
From what SC says it seems coincidental that air represents such a suitable cocktail for an ICE (I suppose one could argue that we would have invented some other motor design if it wasn't!).
I'm not sure how the calculate the engine capacity but I guess it's the total displaced by the pistons. Half the time when the piston is going down it is pulling in air so that's 1.5L 1500 times a minute. That makes 2250 litres of air a minute of which roughly 20% or 450 litres a minute is oxygen.I think most of that oxygen is consumed burning the fuel; having much more or much less air than you need would be wasteful.
But don't the cylinders operate at reduced pressure?
peppercorn, where did you get the number 14.7 from?
What has expansion rate got to do with it?
Am I right in thinking the rate of heat transfer is governed by specific heat capacity. Does this figure also define expansion?
...What's wrong with air? It's so readily available.
Also a 'heavier' gas should, on the face of it, soak up the thermal energy more readily, turning it into expansion - hence less wasted energy & potential for removing cooling system completely.
QuoteAlso a 'heavier' gas should, on the face of it, soak up the thermal energy more readily, turning it into expansion - hence less wasted energy & potential for removing cooling system completely.That doesn't quite make sense to me. Why would it work that way?The bit about Nox's could be relevant tho. But there could be a problem with CO being formed?