Search Results

The flow field inside a steady flow rig is investigated using Molecular Tagging Velocimetry (MTV). The MTV technique is essentially the molecular counterpart of the PIV based approaches, and does not require the use of seed particles. In the work reported here, the fluid velocity data are obtained simultaneously at typically 300 points over a plane. Spatial maps of the instantaneous velocity and vorticity fields are presented. The mean and RMS fluctuation of the two measured components of the velocity vector are in general agreement with the trends reported based on previous single-point LDV measurements in a similar geometry.

This paper presents results from experiments performed in an axisymmetric water analog model of a four-stroke IC engine using the optical velocimetry technique LIPA (Laser Induced Photochemical Anemometry). The investigation can be described as a fundamental scientific inquiry into the fluid dynamics encountered during engine operation, with the long term goal of increasing performance. An application of LIPA to a fluid dynamics problem delivers two-dimensional fields of velocity vectors which are projections of the full three-dimensional vectors in single measurement steps. From an evaluation of a velocity field vorticity information can be obtained readily. Velocity fields and vorticity distributions are, in this study, the basis for the evaluation of seven parametric quantities. Some of these may become tools that give engineers ‘rule of thumb’ indications of the mixing that is occurring.