Intake Manifold Flow Assessment ona 3-cylinder Natural Aspirated Downsized Engine Using CFD and GT-SUITE

In this paper, the intake manifold as the most effective part on engine’s volumetric efficiency was investigated in detail with emphesizing on the flow behavior and characterestics. Eight different designs were prepared and imported to the CFD software. Five objective functions with different weights were applied and investigated by TOPSIS method. The weights were supposed so that, one of the objectives was dominant compared to others. Mass flow rate, mass flow rate deviation between runners, flow coefficient, turbulence intensity and velocity at the runner end were considered as objective functions for flow detail assesment. Then, all geometrical dimentions were applied to a verified ESC. The engine simulation model was developed for I3 engine considering turbulence combustion model named SI-TURB . The ESC was validated by experimental combustion profile data. The experimental and numerical results had good compatibality, so that the ESC could simulate and predict the engine performance by 6.15% accuracy. This paper shows that the hybridization of 3D analysis with ESC in the closed loop way is mandatory for developing of IM in order to have the best compromising design. Finally, combination of CFD and ESC revealed, considering the same weights for objective functions in TOPSIS, good performance in point of engine power out put.