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Design of Engine Intake Manifold of a Commercial Vehicle for Uniform flow Distribution Using Transient CFD Simulation
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on September 22, 2021 by SAE International in United States
Intake manifold is the part of an internal combustion engine that supplies fuel/air mixture to the cylinders. It ensures a uniform mixture at the cylinder inlet for better mixing inside the cylinders to achieve better volumetric efficiency. Uneven distribution of fuel/air mixture causes unstable torque and unburnt fuel which fails to meet the emission norms. It also results in uneven temperatures in some cylinders because of cylinder misfiring. Three-dimensional numerical simulations are carried out to investigate the CNG mass distribution at the inlet of each cylinder. Commercial CFD tool Ansys FluentTM is used to study the velocity and flow distribution of air inside the runners. This study focuses on resolving the engine misfiring issue by optimizing design changes and involving cylinder suction pressure with variable inlet valve opening and closing timings into simulation. Effect of including suction pressure is also discussed in this paper. Transient simulation is performed by defining fresh air mass flow rate as a function of crank angle along with varying pressure profile. varying valve timings are applied according to engine firing order. Air mass flow rate is plotted against crank angle for each cylinder. 10-15% variation in mass flow of air is observed relatively between each cylinder which indicates non uniform distribution of air. This has been corrected by doing design changes and the variation is brought down to 4% between cylinders. Three designs have been compared to get least variation. CFD results are well correlated with Engine test results.
- Tushar Patil - Ansys India Inc.
- Geetesh Waghela - VE Commercial Vehicles, Ltd.
- Ashok Patidar - VE Commercial Vehicles, Ltd.
- Juzer Jaliwala - VE Commercial Vehicles, Ltd.
- Geetesh Waghela - VE Commercial Vehicles Ltd
- Ashok Patidar - VE Commercial Vehicles Ltd
- Juzer Jaliwala - VE Commercial Vehicles Ltd