What Does Charge Mean in Engine Efficiency and Combustion?

[mech-eng]

Homework Statement

combustion adds 1200kj/kg to the charge.
what is the meaning of " charge" here.

Homework Equations

The Attempt at a Solution

 

[SteamKing]

'Charge', especially w.r.t. reciprocating engines, usually means the mixture of fuel and oxidizer admitted to the cylinder for combustion. Can you be more specific about what context you found this phrase?

 

[mech-eng]

'Charge', especially w.r.t. reciprocating engines, usually means the mixture of fuel and oxidizer admitted to the cylinder for combustion. Can you be more specific about what context you found this phrase?

I found this phrase from an introductory thermodynamics book,on the chapter about diesel and
otto cycles.