Case Description​

• ·  Gasoline Direct Injection engine cold flow simulation was performed using SPAM algorithm [1,2]
• ·  Figure 1 shows the geometry of the GDI engine performed in this work.
• ·  Table 1 lists the major specifications of a GDI engine under consideration.

Computational Mesh

• ·  Uniform-sized cells are created using ANSYS Mesher
• ·  The unstructured mesh consists of a total of 310,000 tetrahedral cells at the bottom dead center and 240,000 tetrahedral cells at the top dead center.

Physical Models

• ·  Turbulence Model : Laminar flow

Numerical Method

• ·  First order scheme for spatial discretization of convection term
• ·  Solver ‘turbDyMEngineFoam‘ with a library of S. Menon’s dynamicTopoFvMeshwas used, available in (https://github.com/smenon/dynamicTopoFvMesh).
• ·  Normalized residual of P < 10-5, the other < 10-4 for convergence
• ·  The PISO algorithm was chosen to resolve the coupling between velocity and pressure.
• ·  Total two stroke simulation (720CA) was performed.

Results

• ·  The below figure shows the vertical (y-direction) velocity components at the BDC.
• ·  The blue color represents downward flow into the cylinder, whereas the red color represents flow upward out of the cylinder.