Automotive side mirror surface contamination: An experimental study by Lagrangian Particle Tracking

With the increased use of Advanced Driver Assistance Systems (ADAS) in modern cars, the  field of surface contamination saw a resurgence. To keep the various sensors working properly it is of utmost importance to keep them clean and free of contamination. One way to achieve this is to ensure they are mounted in areas where they can be kept free...

Experimental aeroelastic characterization based on integrated optical measurements

This thesis presents a novel measurement approach for aeroelastic wind tunnel testing. The key novelty of this approach is the integrated measurement of aerodynamic and structural quantities using an optical technique. The considered approach consists of combined measurements of flow tracer particles and structural markers using a Lagrangian...

Rheology study of ballast-sleeper interaction with particle image Velocimetry (PIV) and discrete element modelling (DEM)

Ballast rheology is a phenomenon that describes movements of ballast particles due to the discrete nature, which eventually leads to the ballast bed fluid deformation after a long-time service. In most cases, ballast rheology is the main reason of track irregularity that leads to some track defects, e.g., hanging sleeper and mud spots....

Coaxial volumetric velocimetry

This study describes the working principles of the coaxial volumetric velocimeter (CVV) for wind tunnel measurements. The measurement system is derived from the concept of tomographic PIV in combination with recent developments of Lagrangian particle tracking. The main characteristic of the CVV is its small tomographic aperture and the...

Assessment of the pseudo-tracking approach for the calculation of material acceleration and pressure fields from time-resolved PIV: Part II. Spatio-temporal filtering

The present study characterises the spatio-temporal filtering associated with pseudo-tracking. A combined theoretical and numerical assessment is performed that uses the relatively simple flow case of a two-dimensional Taylor vortex as analytical test case. An additional experimental assessment considers the more complex flow of a low-speed...

Assessment of the pseudo-tracking approach for the calculation of material acceleration and pressure fields from time-resolved PIV: Part I. Error propagation

Pseudo-tracking refers to the construction of imaginary particle paths from PIV velocity fields and the subsequent estimation of the particle (material) acceleration. In view of the variety of existing and possible alternative ways to perform the pseudo-tracking method, it is not straightforward to select a suitable combination of numerical...