Group project · American University in Dubai
Internal Combustion Engine CFD: Otto Cycle
A full four-stroke Otto cycle for one cylinder of a Mercedes-Benz M254 2.0L turbo engine, simulated in ANSYS Fluent across three operating conditions.
- Project
- Internal Combustion Engine CFD: Otto Cycle
- Sheet
- 01 / 04
- Date
- Apr 2026
- Type
- Engineering
Transient simulations
12
Pressure error vs MATLAB
< 5%
01
Setup
Each stroke (intake, compression, expansion, exhaust) was modelled as a separate 2D planar transient simulation, using a dynamic layering mesh for the moving piston. The runs covered Wide Open Throttle, Part Open Throttle and turbocharged conditions: 12 transient simulations in total.
The working fluid was a compressible ideal gas with k-ω SST turbulence closure. Boundary conditions came from a prior MATLAB thermodynamic analysis of the ideal Otto cycle.
02
Results
Pressures matched the MATLAB targets to within 5% in every case. Temperatures ran consistently 9–12% high, which we traced to the constant-speed piston profile (rather than a sinusoidal one) and the ideal-gas assumption in place of a reacting air–fuel mixture.