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The cycle involved in the operation of an internal combustion engine is called the Otto cycle....

  1. The cycle involved in the operation of an internal combustion engine is called the Otto cycle. Air can be considered to be the working gas and assumed perfect. The cycle consists of the following steps.
  1. reversible adiabatic compression from A to B
  2. reversible constant volume pressure increase from B to C (from the fuel combustion)
  3. reversible adiabatic expansion from C to D
  4. reversible constant volume pressure decrease from D to A

Determine an expression for the efficiency of this engine assuming that heat is supplied in step ii). Then evaluate the efficiency for a compression ratio of 10:1. Assume that the ratio of the volumes defines the compression ratio and that state A is defined by V = 4.00 L, P = 1.00 atm, and T = 300 K. Further, let VA = 10·VB, PC/PB = 5, and Cp,m = (7/2)R. Finally, calculate the entropy change for system and surroundings for each step in the cycle.

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