A study of steady flow through a SI engine intake system using CFD

The main objective of the present work was to make a computational study of steady flow through intake manifold, port, valve and valve seat for various valve lifts. Three-dimensional flow within the manifold, port and valve was simulated using computational fluid dynamics (CFD) and the code STAR-CD. Flow structures for the various valve lifts were predicted. The total pressure map from computation provided comprehensive information on the intake region flow. Analysis was carried out for runner 1 at three different valve lifts for various speeds at wide-open throttle condition. A trimmed cell (adjust and cut process based on an underlying structured grid) was adopted for meshing the geometries created in PRO-ENGINEER software. Flow was simulated by solving governing equations, namely, conservation of mass and momentum using the SIMPLE algorithm. Turbulence was modelled by high Reynolds number version of k-ε model. Experimental measurements were made for validating the numerical prediction. Good agreement was observed between predicted result and the experimental data; that valve lift had significant effect on flow field; and that as the valve lift increased flow separation occured near the valve seat region.