Study of the Flow Field Development During the Intake Stroke in an IC Engine Using 2D PIV and 3D PTV FloCoTec, Incorporated

Format:

Conference/Event

Author/Creator:

Choi, WoongChul, author.

Conference Name:

International Congress & Exposition (1999-03-01 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 1999

Summary:

The evolution of the flow field inside an IC engine during the intake stroke was studied using 2 different experimental techniques, namely the 2D Particle Image Velocimetry (2D PIV) and 3D Particle Tracking Velocimetry (3D PTV) techniques. Both studies were conducted using a water analog engine simulation rig. The head tested was a typical pentroof head geometry with two intake valves and one exhaust valve, and the simulated engine operating point corresponded to an idle condition. For both the 2D PIV and 3D PTV experiments, highspeed CCD cameras were used to record the motion of the flow tracer particles. The camera frame rate was adjusted to correspond to 1/4° of crank angle (CA), hence ensuring excellent temporal resolution for velocity calculations. For the 2D PIV experiment, the flow field was illuminated by an Argonion laser with lasersheet forming optics and this laser sheet was introduced through a transparent piston crown to illuminate the center tumble plane. For the 3D PTV experiment, the flow field was illuminated through the same piston crown by a high power stroboscope. A total of 50 intake strokes were recorded for each experiment.Owing to the relatively sparse nature of the 3D data, the results from the 3D PTV were only examined on a phaseaveraged basis to study the evolution of the average 3D flow field at each crank angle. Corresponding phaseaveraged results from the 2D PIV were also generated. The ensembleaveraged 2D PIV results are very similar to the 3D PTV results in the same plane, hence validating the use of the 3D PTV technique to rapidly capture the entire 3D flow field on an ensemble averaged basis. The average flow field generated by this head does not evolve into the final form (tumble and a pair of cross tumble eddies) until late into the intake stroke. Initially, the flow field is very energetic and contains relatively small and concentrated eddies.The better spatial resolution of the 2D PIV allows measurements of the instantaneous flow structures, yielding valuable information about the relatively smaller scale structures of the flow and the cycletocycle variation of these flow patterns. We found that the average flow features are the result of relatively unstable instantaneous flow structures, considerably jittering in space from cycle to cycle. In summary, 2D PIV and 3D PTV are complementary experimental techniques to study intake generated flow fields. The 3D PTV provides a relatively rapid assessment of the complete 3D flow field topology while the 2D PIV yields more localized details about the flow field, as well as cycleresolved velocity information. Therefore, more accurate understandings of the flow field can be achieved by using both techniques on the same problem

Notes:

Vendor supplied data

Publisher Number:

1999-01-0957

Access Restriction:

Restricted for use by site license