The Comparison of Form Drag and Profile Drag of a Wind Turbine Blade Section in Pitching
Extensive wind tunnel tests have been conducted to investigate the unsteady flow field over and behind a 2D model of a 660 kW wind turbine blade section in pitching motion. The surface pressure and wake dynamic pressure variation at a distance of 1.5 chord length from trailing edge were measured by pressure transducers during several oscillating cycles at 3 reduced frequencies and oscillating amplitudes. Moreover, form drag and linear momentum deficit are extracted and compared at various conditions. The results show that the wake velocity field and surface pressure of the model have similar behavior before and after the airfoil beyond the static stall angle of attack. In addition, the effects of reduced frequency and oscillation amplitudes are discussed. Keywords—Pitching motion, form drag, Profile drag, wind turbine.
Unsteady wake measurements of an oscillating flap at transonic speeds
Mesure en soufflerie des profils de sillage stationnaire ou instationnaire d'un profil aerodynamique avec volet oscillant. Mesure des profils de pression et de vitesse en 4 points axiaux. Etude de l'influence de l'angle du volet
Optical emission spectroscopy of self-sustained magnetron sputtering
Abstract The results of plasma investigation during very high power magnetron sputtering processes are presented. Magnetron sputtering during both standard and self-sustained modes was investigated. Owing to very effective target cooling and appropriate magnetic field distribution, the high target power density could be reached (up to ∼1000 W/cm 2 , ∼1.5 A/cm 2 ). A copper target 50 mm in diameter and 7 mm in thickness was used during the experiments. Two modes of magnetron sputtering, i.e. standard and self-sustained, were investigated. Optical emission spectra were measured. The emission intensity of the Cu species as a function of target power density during both magnetron sputtering modes was observed. The spectra were observed in the 200–800 nm wavelength range. When target current rose, the emission intensity of copper ion lines increased and neutrals ones decreased.