Congratulations to Bruce Oliver of Chapel Hill, Tennessee! He is our August “ASE Question of the Month” prize winner!
Every month, we host an ASE-style question related to a feature article in the current issue of Motor Age. In August, the question was:
HCCI stands for ______________.
A. Homogenous Cylinder Charge Ignition
B. Homogenized Cylinder Charge Insertion
C. Hydrogen Charged Cylinder Injection
D. Homogenous Charge Compression Ignition
If you selected “D”, you’re correct!
HCCI stands for “Homogenous Charge Compression Ignition”.
Homogenous Charge (HC) refers to the charge state prior to ignition. A substance is homogeneous if its composition is identical wherever you sample it. This means that the charge mixture (fuel and air) has a uniform composition throughout the cylinder.
Compression Ignition (CI) refers to the method that is used to drive the fuel past its autoignition point. When air is compressed rapidly, the molecules are accelerated off of the moving piston where they hit one another. The kinetic energy from the piston is turned into vibrational energy of the atoms causing a heating effect. This process is called Adiabatic Compression. The Adiabatic processes are characterized by zero heat transfer with the surroundings. In the case of rapid compression, the process occurs too fast for any heat transfer to occur. Heat transfer is a slow process. This rapid compression of the air creates a rapid heat increase that is used to drive the fuel well past its autoignition point.
And whether you answered correctly or not, you are still eligible to enter the drawing, sponsored by Federated Auto Parts. So give it a shot! Take the September quiz now!
