Quote:
Originally Posted by NeilBlanchard
The Revetec design doubles the efficiency of a crankshaft design. If some of the other major losses could be addressed, then could the efficiency go above 50%? Is 60% possible?
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It really depends on useful work obtained vs. thermodynamic heat input. Try modelling a Carnot cycle, using assumptions for Otto cycle, Miller cycle, and whatever other cycles you want. That'll answer your question in theory.
Quote:
Originally Posted by NeilBlanchard
The major problems with most current ICE designs:
Poor geometric / mechanical torque due to the inherent limitations of the sinusoidal motion of the piston and the connecting rod's angle relative to the crankshaft (vs a rotary design or an electric motor)
Long time periods between power strokes, requiring relatively large flywheels.
Large mechanical drag from the valvetrain having to work against the springs.
The acceleration and deceleration of the piston and connecting rods.
The brief / momentary pressure buildup of the fuel burn (vs the constant pressure reserve of a head of steam, for example)
The need to pump oil through tiny passageways, and to generate electricity.
The need to warm up to reach ideal operating temperature.
The amount of waste heat requires a lot of "stuff" and requires a lot more aerodynamic drag to be able to dump it out of the vehicle.
The relatively narrow torque band, requiring a multi-ratio transmission -- basically as many gears as possible. Seven or eight gears would be better than merely three to five.
The need to idle while not actually being used.
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If we're talking about the majority of cars on the road today, you forgot a couple of biggies.
The need to generate an intake manifold vacuum.
The need to suck air past a huge inefficient restriction (namely, the throttle plate).