EGR - A Challenge for Modern Plastic Intake Manifolds 2002-01-0902
Nowadays, market shares for plastic intake manifolds are still increasing, although the competition with aluminum and magnesium is tough , .
It is becoming more and more apparent, that for a further spread one of the key issues is the managing of high temperatures generated by EGR inlets. Successful design of such devices will depend heavily on the correct prediction of the temperature loads.
3-D CFD calculations (e.g. with STAR CD or Fluent) turn out to be a valuable tool for this purpose. However, providing realistic boundary conditions remains difficult unless measured engine data for EGR mass flows and temperature is available.
The alternative to experimental data is the calculation of boundary conditions with the help of a 1D charge cycle program, e.g. GT Power, which serve then as time dependent, tabulated input for the CFD codes.
However only the full coupling of the 3D computational domain representing the manifold with the 1-D charge cycle program assures that a real two way dependence of engine and manifold is achieved thus leading to more exact results. The present paper will describe this procedure in more detail. Time dependent exhaust gas distributions will be analyzed and the wall temperatures for cylinder individual EGR determined. Conclusions will be drawn regarding required materials and design modifications for reduced temperature load.