P. Henrik Alfredsson

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This article reports on one component of a larger study on measurement of the zero-pressure-gradient turbulent flat plate boundary layer, in which a detailed investigation was conducted of the suite of corrections required for mean velocity measurements performed using Pitot tubes. In particular, the corrections for velocity shear across the tube and for(More)
Pressure sensitive paint (PSP) was used to measure pressure on the blades of a radial compressor with a 51 mm inlet diameter rotating at speeds up to 50 krpm using the so called lifetime method. A diode laser with a scanning-mirror system was used to illuminate the paint and the luminescent lifetime was registered using a photo multiplier. With the(More)
For pressure-driven turbulent channel flows undergoing spanwise system rotation, it has been observed that the absolute vorticity, i.e., the sum of the averaged spanwise flow vorticity and system rotation, tends to zero in the central region of the channel. This observation has so far eluded a convincing theoretical explanation, despite experimental and(More)
This paper reports the first turbulence measurements performed in the Long Pipe Facility at the Center for International Cooperation in Long Pipe Experiments (CICLoPE). In particular, the Reynolds stress components obtained from a number of straight and boundary-layer-type single-wire and X-wire probes up to a friction Reynolds number of 3.8×104 are(More)
The evolution of small-scale structures in homogeneous isotropic turbulence. A description of eddying motions and ow patterns using critical-point concepts. 8 visually browse through the list of objects via the diagnostics box (gure 10). Dierent variables can be examined simultaneously. In this way a eld can be visualized (e.g. vorticity magnitude)(More)
27 Streamwise evolution of longitudinal vortices in a turbulent boundary layer 59 Three-dimensional instabilities of oscillatory equatorial zonal shear flows 75 Transport of inertial particles by Lagrangian coherent structures: application to predator–prey interaction in jellyfish feeding 85 The dynamics of the transitional flow over a backward-facing step(More)
Wind energy is one of the fastest growing sources of sustainable energy production. As more wind turbines are coming into operation, the best locations are already becoming occupied by turbines, and wind-farm developers have to look for new and still available areas-locations that may not be ideal such as complex terrain landscapes. In these locations,(More)