Numerical optimization of a 6-cylinder diesel engine intake and exhaust manifold

Exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. By recirculating a portion of an engine's exhaust, inert gas displaces combustible matter in the cylinder. Because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR decrease the amount of NOx combustion generates. This project aims at optimizing the location of the EGR ports, which are crucial to the operation and efficiency of the EGR system. The Computational Fluid Dynamics (CFD) code ANSYS FLUENT was used to analyze the intake and exhaust manifold working processes. In order to conduct numerical optimization on determining the best EGR port location, a transient CFD model was developed. Real operational transient boundary conditions were applied to the model by using user defined functions (UDF), and the results of flow characteristics and EGR distribution were analyzed in details. The EGR mass flow rate mal-distribution was presented at the transient simulation. In this thesis, a series of Computational Fluid Dynamics (CFD) simulations will be performed for the diesel engine intake manifold design. Data provided by LHP Software Solutions will be employed in these simulations. Simulation results will present detailed information regarding the airflow through the intake manifold and the temperature gradients along the engine cylinders. These results will provide a clear idea about the flow round the plenum chamber.