Splash & Go writes:
"Green Flag: Hybrids & KERS"
Posted by Uptight Motorsports Nerd on January 2, 2011
Viewed 758 times
Continuing the series of environmentally sound technologies entering the world of motorsports, we focus on hybrid engines and KERS. First, it is important to clarify the difference between the two technologies. Hybrid engines combine two power plants (usually internal combustion and electric), each of which is capable of propelling a vehicle independently of the other. Kinetic Energy Recovery Systems (KERS) merely represents technology that recycles waste energy and can be retrofit onto a conventional engine; it cannot propel a vehicle alone.
Hybrid gas engines are more complex than their conventional brethren. They use an Atkinson cycle engine rather than the conventional Otto cycle. This involves connecting the connecting rods to fulcrums with two pivot points making the exhaust and compression strokes different lengths. Due to the fulcrum?s presence, only one-quarter of a rotation of the crankshaft is needed is needed to complete a single stroke, putting the crankshaft at a 1:1 ratio with the camshaft.
Hybrid electric motors usually run alternating current from a battery with an inverter. If the battery runs low, the gas engine can charge it. The circuit?s voltage varies between manufacturers. What?s important is the power output of the motor. For example, the electric motor output on a Honda Insight is 13 horsepower, while the electric motor on the Ford Fusion Hybrid is 106. When moving from a dead stop, the Insight must accelerate slowly or it will need to start the gas engine for more power; the Fusion does not need the gas engine until it reaches higher speed.
KERS can use a battery and motor (similar to hybrids) or it can use a mechanical flywheel that can store potential energy during deceleration and release it during acceleration. A battery would only be charged during braking and not by the engine. There?s no special engine to build and it can be retrofit onto an existing model. Both systems offer the advantage of recycling waste energy through regenerative braking.
In terms of racing applications, road racing and short tracks offer great potential for hybrid power plants. On large ovals, however, a hybrid engine would be hindrance. For example, at Talladega, the electric motor (and battery) on a hybrid would only be useful getting in and out of the pits, and then it?s just extra weight until the next pit stop. KERS being less complex and lighter than a true hybrid system would still be somewhat useful on big ovals, even if slightly less efficient elsewhere.
In either scenario, the spectacle of racing itself is unchanged. The sound of a hybrid may make a yellow period a tad more serene, but at high speed, something a little more internal combustion is in order.
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