Design and Development of a Restricted Intake Manifold for a Naturally Aspirated Four Cylinder SI Engine

Intake manifold is one of the principal components of the engine system in the vehicle. The air intake manifold is the passage for air into the engine and thus affects the amount of air quantity. The objective of the present work is to design and development of a strong, reliable and light weight intake manifold for a multi cylinder spark ignition engine. The developed manifold will improve the airflow intake and provide equal mass flow rate in all runners to create better performance. In the present work, combinations of 1-D modeling using Ricardo Wave and CFD simulations on Star CCM+ were employed to substantiate the modeling. The designed manifold is ensured to have a throat velocity of the restrictor close of Mach 1and the plenum was simulated to have a zero velocity creating maximum pressure close to atmospheric pressure. The necessary structural strength to the intake manifold was ensured by performing FEA simulations using ANSYS software. Rapid Prototyping Technique was selected to avoid any disruption in the fluid flow and vortex formations among which Selective Laser Sintering Technique was selected based on decision matrix keeping in mind the strength, reliability, precision and light weightiness of intake components. Following this the testing and validation was carried out on a chassis dynamometer. In comparison with the last intake, there was a torque increment of 7 N-m in the operating engine rpm range, which was accompanied with a variation of nearly 3% in mass flow rate between the four runners. Also, performance curves of the simulation model and dynamometer testing exhibited close resemblance, corroborating the intake model boundary conditions.