Simulation of Engine

The simulation is carried out in STAR CD – 4.22 version, which uses a polyhedral trimmed moving mesh This RANS simulations are conducted using a workstation with 12 cores and took about 3 days for RNG and 7 days for turbulence model for 3 full cycle simulations. In this computation, the suction TDC starts at 360 CAD (Crank Angle Degree) and ends at 540 CAD. Compression starts when piston is at 540 CAD and ends at 720 CAD. The measured variation of pressure at the inlet with crank angle is used for this simulation. The boundary conditions, in terms of pressure 0.95 bar, are specified at the inlet of the intake port, which is located at about 10dp from the neck of the branch [1]. The simulated boundary condition data collected are in steps of 5 CAD from 0 CAD TO 720 CAD. A lengthy duct is included in the model so that the flow conditions at the intake port entrance are appropriate and do not need approximation. This also ensures the correct fluid mass with sensible turbulence level enters the cylinder as the flow evolves through the inlet duct. As stated in the literature [2] the pressure and temperature at the exit of the exhaust duct are specified to be 1.1 bar and 316.7 K respectively. The cylinder walls are specified to be isothermal at 400 K, the piston crown is at 500 K and the cylinder head is at 333 K. The turbulence conditions at the inlet are specified in terms of intensity as 5 % and length scale as 0.01 mm.