Vortex velocimetry of air flows using Helium Filled Soap Bubbles (HFSB)

This thesis work illustrates the first of its kind solution to this problem of lack of seeding at vortex core in air flows, by the use of Helium Filled Soap Bubble (HFSB) which is a neutrally buoyant tracer particle in air flows. To analyse the lack of seeding in the vortex core, a 2D numerical simulation of particle motion in vortex flow is...

Estimation and reduction of peak-locking errors in PIV measurements

In PIV, the systematic tendency of the measured sub-pixel displacement to be biased towards the integral pixel values is called peak-locking. This occurs when the particle image diameter is less than a pixel. The bias error causes inaccuracy in the measured PIV data which does not reduces with increase in the sample size. Recently developed...

On the tracing fidelity of helium-filled soap bubbles for PIV experiments

This thesis follows a previous study on the aerodynamic characterization of helium-filled soap bubbles (HFSBs) for large-scale PIV measurements and aims at characterizing statistically the tracing fidelity of HFSBs in PIV experiments, considering the statistical distribution of the bubbles diameter, slip velocity, relaxation time and density....

Experimental analysis of the flow around a cylinder with a square cross-section

The present work investigates the flow around a two-dimensional square section object at varying angles of incidence. The experimental approach employs Particle Image Velocimetry for the determination of the time-averaged velocity field and the unsteady large scale coherent variations (e.g. vortex shedding) as well as turbulent fluctuations. The...