Three Dimensional Flow Measurements Within the Cylinder of a Motored Four-Valve Engine Using Holographic Particle-Image Velocimetry

A Holographic Particle-Image Velocimetry (HPIV) system is developed to investigate the in-cylinder flow in a motored four-valve engine operated at 1500 rpm. Image aberrations introduced by the optical liner of the engine are optically eliminated using complex-conjugate hologram reconstruction that allows measurements near the cylinder walls also. High-resolution velocity measurements in different axial planes of the in-cylinder flow are made at crank angles from 60° to 285° ATDC. Prospects and limitations to full three-dimensional extension of the HPIV system are discussed. The results show the development of the in-cylinder flow in two planes with emphasis on large and small-scale flow structures.