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The aim of the paper is to present some practical aspects of PIV recording set-ups which are not often discussed in the literature. After a short presentation of the different possible light sources available, emphasis is put on the Nd:YAG laser which has contributed to the strong evolution of PIV. Then the elements needed to realize a light sheet from a laser source are presented and discussed. Finally, the basic optics knowledge needed to record good particle images is recalled with emphasis on points of importance for PIV.

This study focuses on the corner flow separation occurring in a simplified wing-body junction composed of a NACA0015 twisted wing mounted on a flat plate at a Reynolds number based on the wing chord of Re c 1.2 × 10 6 . Wind-tunnel test measurements are carried out in the corner area including extensive oil-flow visualizations, high speed particle image velocimetry and unsteady pressure sensors. The analysis of the experimental database shows that the corner flow separation creates mean flow distortions that induce high anisotropy in the Reynolds stresses and turbulent kinetic energy. The wall pressure spectra show a broadband hump associated with the corner flow separation at St δ 0.04, based on the incoming boundary layer thickness. A sensitivity study indicates the progressive growth of the corner flow separation with increasing angle of attack, leading to complete wing stall and the delay of the corner flow separation onset when the incoming boundary layer is thicker.

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An ipsilateral upper neck trigger point was found in 21 of 24 patients with unilateral headache. During the prodromic period this trigger point was detected as a tender protrusion on neck palpation. In 18 out of 24 patients it was also found during the headache-free period. On standard roentgenogram, this protrusion seemed to be a laterally developed C2 spinous process. The EMG study showed latent trapezius hypertonicity on the side of the headache, even during the headache-free period. The association of the painful protrusion and trapezius hypertonicity could create an autoreinforcing nociceptive loop, which in turn could be the cause of lateralization of the pain.