Intake port flow characteristics are critical in determining the overall performance of diesel combustion systems. In-cylinder flows created during the intake stroke influence fuel-air mixing, bulk charge motion and turbulence generation. The flow capacity of the intake port is also a key factor in determining volumetric efficiency. The relationship between intake port geometry and Performance has long been a subject of interest to
many researchers, although as yet a comprehensive understanding remains elusive. Swirl is created by bringing the intake flow into the cylinder with an initial angular momentum. While some decay in swirl due to friction occurs during the engine cycle,
intake generated swirl usually persists through the compression, combustion and expansion processes. In engine designs with bowl-in-piston combustion chambers, rotational motion set up during intake is substantially modified during compression.
Engine Development Lab at ARAI carries port testing for Mean Swirl and Mean Flow Co-efficient of intake port and exhaust port on a dedicated test rig. Paddle Wheel Method and Impulse Swirl Method are being used to test ports.