Calculation of Three Dimensional Air Motion in Model Engines

Calculations are described of three-dimensional air motion in two motored model engine configurations and comparisons are made in one Instance with experimental data. The predictions were obtained using a newly-developed multidimensional method which has the following main features: a combination of expanding/contracting and curvilinear grid systems which can accommodate a range of practical engine configurations; finite volume discretisation; an Implicit, non-iterative solution algorithm; and, in the present application, a two-equation turbulence model. The two test cases involve off-centre annular- orifice and poppet-valve inlet/exhaust arrangements respectively, both of which generate complex flow structures, especially during Induction. The predictions for the former case show only moderate agreement with the data and point to the need for improved discretisation practices, among other aspects.