where dQ/dQ is the heat release rate per crank angle, Q is crank angle, P is the pressure, V is the cylinder volume, and g is the specific heat ratio which is taken to be 1.37 during compression and 1.30 during expansion. More detailed methodologies of calculating experimental heat release considering constant specific heat ratio can be found in Ref. [38]. Considering for urban application engines are mostly operating under mid load conditions, experimental and numerical operating cases are selected based on this criteria. Hence, two experimental cases, namely case-1 and case-2, with engine speeds of 1200 rpm and 2400 rpm and 50% load condition are selected to perform the simulations. For commencing simulations, boundary and initial conditions are taken from the experiments and used as inputs in computational code. Table 3 shows the mentioned input parameters.