Now that is very clever, change the parameters of your argument.
You were talking about the Otto cycle, not the Brayton cycle
Sorry Blackhand, you really have missed the boat here.
I originally chose to talk about the Otto cycle because I thought it was easier to explain why thermodynamic efficiency goes up with higher compression of the fluid. The fact is that in both the Otto and Brayton cycles, more compression before the combustion results in less heat exchange to the fluid - and a thermodynamically more efficient engine.
I obviously made a mistake, because I didn't count on people like yourself and Oggers being unable to understand such a simple concept. Oggers then went off on several tangents, and used a myriad of false arguments about ignition timing, and valve timing, and mixing, and flame fronts, and all sorts of other things to try and squeeze his way out of the fact that nothing of those things have to do with the original question about the thermodynamic efficiency of higher compression.
gents, are you talking turbines or pistons ? valve timing in a turbine ? when it comes to turbine engines we also discuss pressure ratio, not compression. maybe its just a misunderstanding since different things are mixed up.
Hi Aerobat. Yes, these things don't occur in a turbine - this was the point I was trying to make. Oggers used these arguments (valve timing, fuel mixing, incomplete combustion, VE at low throttle) as his reasoning for the difference between the efficiencies of high and low compression engines.
My switch over to turbine was to show that his arguments don't apply on a turbine, where in fact the same thermodynamic principle does (higher compression before combustion results in less energy wasted heating the fluid = more available work).