High-speed 3D Measurements of the Influence of Intake Pressure on the In-Cylinder Flow in a DISI Engine

To improve the performance of internal combustion engines, novel engine techniques, e.g., CAI or HCCI, aim at an instantaneous ignition of a homogeneous mixture formation. Because the mixture formation is provided by the time-dependent three-dimensional in-cylinder flow and subject to several input parameters, volumetric high-speed measurements are required for extensive investigation. In this study, the impact of three intake pressures on the engine flow in a DISI engine is analyzed using high-speed tomographic particle-image velocimetry. The investigation reveals a slight influence of the intake pressure on the large-scale flow structure, the tumble vortex, and the in-cylinder velocity distribution.