In December 2003, the Physikalisch-Technische Bundesanstalt (PTB) started the development of an optical-based primary flow rate standard for application in natural gas under high pressures (up to 5.5 MPa). The concept underlying this technology will be presented in this paper. The technical approach is based on the application of a conventional laser Doppler velocimeter (LDV) as well as on a ne...

The present study deals with a laser Doppler dual-incident-beam velocimeter in reference-beam configuration developed at the Water Jet Lab of the Dipartimento di Meccanica of the Politecnico di Milano and especially designed for water jet applications. The applied experimental procedure makes it possible, once identified the contributors to the uncertainty of the measurand, to apply an analysis...

This study deals with the particle size measurement of nine aerosol metered dose inhalers. Calibration was made possible by the use of a laser particle velocimeter (aerodynamic Particle Sizer from TSI). The count median aerodynamic diameters (CMAD) show little variation, from 0.63 to 0.73 micron, with standard deviations (sigma g) between 1.2 and 1.8. Aerodynamic diameter aerosol diagram analys...

This paper presents a three dimensional nonlinear finite element analysis for Concrete Filled Steel Tube (CFST) columns subjected to lateral impact load. The finite element models were developed using commercial code ABAQUS/Explicit, which were validated against the experimental results. The study has been carried out to examine the influence of several parameters such as the length of the tube...

A turbulent mixing layer in a water channel was observed at Reynolds numbers up to 3 x los. Flow visualization with dyes revealed (once more) large coherent structures and showed their role in the entrainment process; observation of the reaction of a base and an acid indicator injected on the two sides of the layer, respectively, gave some indication of where molecular mixing occurs. Autocorrel...

Single headed 3D Laser Doppler Velocimetry (LDV) geometries generally rely upon the use of 3 Doppler difference channels, inclined at differing angles with respect to the mechanical axes of the probe. The transformation between the non-orthogonal measurement co-ordinate system and the Cartesian system can result in large errors in the calculated velocities. A theoretical analysis of the geometr...