Diagnostic of In-Cylinder Tumble and Swirl Motions of a Four-Stroke Cycle Engine Subject to Modulation of Inlet Port

• Main Authors: Chih Wei Huang, 黃志偉
• Other Authors: Rong Fung Huang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/61094028359373486278

碩士 === 國立臺灣科技大學 === 機械工程系 === 91 === A particle image velocimeter (PIV) was employed to study the dynamic flow patterns in the cylinders of on internal-combustion engine. The PIV system was developed and integrated in the laboratory. The PIV technologies were tuned in multiple phases in order to fit the applications. For instance, a test rig with very small vibration amplitudes, a seeding mechanism with large dispersion capability, a low electronic-noise image grabbling strategy, a high transparency/low light reflectivity engine cylinder, etc., were integrated in the system. The dynamic flow patterns during intake and compression strokes in the symmetry plane and the cross-section plane, which were vertical to the central axis of the cylinder, were measured. Two different types of mechanical mechanisms were employed to modulate the in-cylinder flame: the off-set inlet port and the inlet air deflection valve. Velocity vector fields and streamline patterns related to the characteristics of the cycle variations were presented. The ensemble-averaged streamline patterns clearly showed the dynamic behaviors of the flows under different arrangements of the inlet mechanisms. Quantitative analysis regarding the tumbles ratios and swirl ratios were conducted for the measured velocity data. The results showed that the application of PIV to the complicated dynamic flow field in a internal combustion engine was adequate. The premier factors affecting the in-cylinder tumble and swirl motions were discussed.