Simulation of Intake System for Two Cylinder Naturally Aspirated In-Direct Injection Engine

This paper summarizes the approach towards the process of computational simulation of the intake system and its experimental investigation. It is an important aspect to improve breathing of the diesel engines for performance, torque smoothening and emissions. This can be achieved by optimizing intake system parameters such as plenum volume, diameters, length of ports & runners, etc., which directly correlates the volumetric efficiency, thereby the performance of the engine. Keeping the objective of improving volumetric efficiency to achieve low-end performance, the intake system design optimization has been done on a twin cylinder, four cycle, compression ignition, In-Direct Injection (IDI) engine. For the simpler intake system, the primary pipe length & diameter can be calculated by mathematical formula applying Helmholtz Resonator principle. But, for a complex intake system, simulation software is used here. Here the intake system is optimized for the volumetric efficiency and intake depression by generating several intake models and simulating it with various combinations of pipe diameters, lengths and plenum volumes. Using simulated results, an intake system has been chosen without generating many prototype models, which has helped in reduction of development efforts, time and cost.