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EGR coolers are used in combustion engines to reduce NOx emissions. However, heat transfer in these coolers also results in thermophoresis-temperature-gradient driven motion of suspended particles towards cooler regions-which leads to significant soot deposition. Presenter Meisam Mehravaran

EGR coolers are used in combustion engines to reduce NOx emissions. However, heat transfer in these coolers also results in thermophoresis-temperature-gradient driven motion of suspended particles towards cooler regions-which leads to significant soot deposition. A simple one-dimensional model is proposed to predict the deposition velocity and soot layer thickness that compares reasonably well with experimental data. The behavior of soot deposits on cooled surfaces is complex, with the thickness of the soot layer stabilizes after around 100 hours, reaching a uniform, thickness over the entire heat-exchanger surface. An analysis of this trend and a tentative mechanism to explain this type of behavior is given, based on experimental observations.

In this article, the behavior of a typical air-to-air heat exchanger (intercooler) during the thermal shock test has been recorded during which the heat exchanger is exposed to very high temperature gradients. Different CAE models have been built that have different levels of details and the sensitivity of the results to the details has been studied. Finally a comparison have been made between the results of the CAE/CFD model and the experimental data and the correlation study shows that in spite of being simple, the dual stream is very accurate and correlates pretty well with test data. Including all design details in the CAE model will not necessarily improve the accuracy of the model while adding up to the computational cost.

Underhood thermal management is a challenging problem in automotive industry. In order to make sure that vehicle works efficiently, there should be enough airflow through the cooling system so that the consequent heat rejection would be adequate. In idle condition the required air flow is provided by the cooling fan so a better understanding and an accurate predictive CAE tool for fan is very beneficial. Computational Fluid Dynamics (CFD) has been extensively used in predicting aerodynamic performance of automotive components. In the current work, the airflow performance of a fan, shroud and radiator assembly was simulated using Moving Reference Method (MRF) method. Although it is less expensive than Sliding Mesh (SM) method, the CAE results compare well with the test data. The simulation was carried out over 10+ different shrouds and the effect of geometrical parameters on airflow was investigated.