EXAMPLE PROBLEM $3-1$A four$-$cylinder, $2\mathrm{.}5-$liter, SI automobile engine operates at WOT on a four$-$stroke air$-$ standard Otto cycle at $3000$ RPM$.$ The engine has a compression ratio of $8\mathrm{.}6$:$1,$ a mechanical efficiency of $86\%,$ and a stroke$-$to$-$bore ratio S$/$B $=1\mathrm{.}025.$ Fuel is isooctane with AF $=15,$ a heating value of $44,300$ kJ$/$kg$,$ and combustion efficiency n $=100\%.$ At the start of the compression stroke, conditions in the cylinder combustion chamber are $100$ kPa and $60\backslash$deg C$.$ It can be assumed that there is a $4\%$ exhaust residual left over from the previous cycle.Do a complete thermodynamic analysis of this engine.For one cylinder: Displacement volume: Va $=2\mathrm{.}5$ liter$/4=0\mathrm{.}625$ L $=0\mathrm{.}000625$ m$^3$ dFor the example problem $3\mathrm{.}1,$ if the expansion is increased so that the pressure at the end of the power stroke is the atmospheric pressure $($Atkinson cycle$)$ obtain:$1.$ the expansion ratio$2.$ the extra work gained$3.$ the efficiency$4.$ the exhaust temperature