3-dimensional particle image velocimetry based evaluation of turbulent skin-friction reduction by spanwise wall oscillation

The reduction of turbulent skin-friction drag and the response of vortical structures in a zero-pressure gradient, turbulent boundary layer subjected to spanwise wall oscillation is investigated using planar and tomographic particle image velocimetry (PIV). The experiments are conducted at a momentum based Reynolds number of 1000, while the...

Resolving vorticity and dissipation in a turbulent boundary layer by tomographic PTV and VIC+

The existing time-resolved tomographic particle image velocimetry (PIV) measurements by Jodai and Elsinga (J Fluid Mech 795:611–633; Jodai, Elsinga, J Fluid Mech 795:611–633, 2016) in a turbulent boundary layer (Re_θ = 2038) are reprocessed using tomographic particle tracking velocimetry (PTV) and vortex-in-cell-plus (VIC+). The...

On the resolved scales in a turbulent boundary layer by tomographic PIV and PTV aided by VIC

Tracking of vortices in a turbulent boundary layer

Eulerian and Lagrangian views of a turbulent boundary layer flow using time-resolved tomographic PIV

Coherent structures and their time evolution in the logarithmic region of a turbulent boundary layer investigated by means of 3D space–time correlations and time-dependent conditional averaging techniques are the focuses of the present paper. Experiments have been performed in the water tunnel at TU Delft measuring the particle motion within a...

On the velocity of ghost particles and the bias errors in Tomographic-PIV

The paper discusses bias errors introduced in Tomographic-PIV velocity measurements by the coherent motion of ghost particles under some circumstances. It occurs when a ghost particle is formed from the same set of actual particles in both reconstructed volumes used in the cross-correlation analysis. The displacement of the resulting ghost...

Three-dimensional vortex organization in a high-Reynolds-number supersonic turbulent boundary layer

Tomographic particle image velocimetry was used to quantitatively visualize the three-dimensional coherent structures in a supersonic (Mach 2) turbulent boundary layer in the region between y/? = 0.15 and 0.89. The Reynolds number based on momentum thickness Re? = 34000. The instantaneous velocity fields give evidence of hairpin vortices aligned...

Three-dimensional instantaneous structure of a shock wave/turbulent boundary layer interaction

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

Lagrangian and Eulerian views into a turbulent boundary layer flow using time-resolved tomographic PIV

Experimental investigation of the instantaneous spatial flow organization of high-speed boundary layers

Tomographic 3D-PIV and Applications

Investigation of a turbulent spot and a tripped turbulent boundary layer flow using time-resolved tomographic PIV

In this feasibility study the tomographic PIV technique has been applied to time resolved PIV recordings for the study of the growth of a turbulent spot in a laminar flat plate boundary layer and to visualize the topology of coherent flow structures within a tripped turbulent flat plate boundary layer flow. The experiments are performed around ...

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...