Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/40437
The goal of this project is to investigate whether the erosion at the leading edge of a wind turbine blade due to collisions with particles in the surrounding flow can be simulated in part by a simple laboratory experiment of strained turbulent flow. For this purpose, box turbulence is generated by rotating impellers, and subsequently undergoes axisymmetric straining motion with mean nominal strain rates of 4 s^(-1)and 8 s^(-1). Particles of varied inertia are seeded in the flow, and the dynamics are investigated through high-speed Lagrangian Particle Tracking (at 10,000 frames per second). Displacements and velocities of the particles are extracted, and flow characteristics are studied through Particle Image Velocimetry measurements. Several flow characterization cases are considered in order to assess the particles collision ratio with an imagined blade leading edge stationed at the stagnation point of the flow. The results show that the larger and denser particles used in this study (and thus of higher Stokes number) were less likely to impact the leading edge than smaller (close to neutrally buoyant) particles. Reducing the turbulence intensity decreased the collision rate of both types of particles in the experiment, and the intensity of the mean strain rate was found to increase collision rate. Although the results are not entirely consistent with expectations (in particular the dependence on Stokes number), it is concluded that a simple experiment of this type presents some advantages and opportunities to systematically study leading-edge erosion and fouling.