Optimization of a Cooling Circuit in an Internal Combustion Engine for Marine Applications

An optimization study involving both fluid-dynamic and thermostructural aspects has been carried out for a 2200 cc turbocharged engine head for marine applications. In this cross-disciplinary problem, the structural and thermodynamic aspects have been decoupled. A preliminary set of CFD numerical analyses of the cooling jacket layout has been performed, in order to investigate critical aspects of the present configuration and improve the cooling performance, by means of local flow patterns and flow distribution analysis. At a second stage, temperature distributions within the metal cast parts have been derived from CFD in order to assess the fatigue strength of the component with structural finite elements. A proper choice of both CFD methodology and boundary conditions is carried out in order to determine a trade-off between computational effort and actual engine behavior representation. The proposed modelling procedure allows a sensitivity study to be carried out of the engine head to variations of the leading geometric parameters, thus devising an optimized component. The methodology favored in this study is finally applied to carry out a comparison between the basic configuration and a fluid-dynamic improved solution, in order to estimate the effectiveness of the design optimization on the fatigue strength of the component.