Time-dependent behaviour of the recirculation region behind an axisymmetric bluff-body

Organization of an axisymmetric turbulent wake in presence of a central protrusion

Stereoscopic Particle Image Velocimetry (PIV) was used to study the wake of an ogive-cylinder with after-body at a diameter-based Reynolds number ReD = 6.7 · 104. The vertical fluctuations reduced from a maximum of 0.18 U? in absence of rear-protrusion, up to 0.12 U? and 0.1 U? when the main-body to after- body diameter ratio d/D was increased...

Decay of the turbulent wake from the supersonic micro-ramp

The wake resulting from two micro ramps operating in a supersonic boundary layer at Ma = 2:0 is investigated by means of PIV. Two micro ramps are investigated with height of 60% and 80% of the undisturbed boundary layer with thickness of 5.2 mm. The measurement domain encompasses the range from 10 to 32 ramp heights downstream of the device. The...

Wing flexibility effects in clap-and-fling

The work explores the use of time-resolved tomographic PIV measurements to study a flapping-wing model, the related vortex generation mechanisms and the effect of wing flexibility on the clap-and-fling movement in particular. An experimental setup is designed and realized in a water tank by use of a single wing model and a mirror plate to...

Wing flexibility effects in clap-and-fling

The work explores the use of time-resolved tomographic PIV measurements to study a flapping-wing model, the related vortex generation mechanisms and the effect of wing flexibility on the clap-and-fling movement in particular. An experimental setup is designed and realized in a water tank by use of a single wing model and a mirror plate to...

Advanced PIV techniques for the temporal and spatial characterization of turbulent structures in high speed flows

Transonic airfoil aerodynamic characterization by means of PIV

PIV-based surface pressure and aerodynamic loads determination on a transonic airfoil

Instantaneous planar pressure field determination based on time-resolved Stereo-PIV

Characterization of flow unsteadiness in a shock wave turbulent boundary layer interaction by means of dual-PIV

Instantaneous planar pressure field determination around a square-section cylinder based on time resolved stereo-PIV

Modeling of particle imaging through shock waves

In compressible flows particle imaging, as done in Particle Image Velocimetry (PIV), is far from trivial. The inhomogeneous refractive index field can cause aero-optical aberrations including blurring of the image, especially near optical interfaces such as shock waves. The understanding of the process causing particle image blur (or blurring of...

The effect of particle image blur on the correlation map and velocity measurement in PIV

In PIV particle image blur is usually observed near fluid optical interfaces, i.e. shock waves, and thin flow structure with large density variations, e.g. shear layers and boundary layers. In such an environment the particle image is not only subject to blur, but is also displaced from its actual position due to refraction, which is denoted as...