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11	Lifting body design and CFD analysis of a novellong range pentacopter, the TILT LR drone / Design och CFD analys av lyftgenererande ytor för "the TILTLR drone",en ny drönare med fem propellrar för lång räckvidd Catagay, Daniel, Yuan, Haoqian January 2016 (has links) In the thesis, a lifting body has been designed aiming to generate lift force for the pentacopter,called TILT LR (Long Range), at higher velocities during flights to improve the aerodynamicperformances. The configuration, which is used as the skeleton of the long range drone for upto 75 kilometers flights, is based upon a tilting system allowing the rotors to rotate around theirown axis in both pitch and roll angles. This offers the possibility to the TILT LR flying withoutany vertical excess thrust at a proper angle of attack and velocity. This new drone can be directlyapplied to missions require long flight time or cover long distance, such as Search & Rescue(SAR), power lines and off-shore structures inspection, fire monitoring or surveillance.Several main CAD models have been created during the process of design and presented in thereport together with the final design. For each model in the process, CFD simulations have beenapplied to observe the behaviors of the flows around the surfaces of the body during steadyflights, followed by a brief analysis for further modification. A series of simulations withvarying velocities and angle of attack have been performed for the final design, analyzing itsperformances under different air conditions. Flight envelope of the design has been presentedalso, together with some ideas of possible further studies on the pentacopter. Lifting body CFD Mesh Multi-rotor Drone Aerodynamic Simulation y-plus Aspect ratio Engineering and Technology Teknik och teknologier
12	Multi Rotor Wind Turbine Design And Cost Scaling Verma, Preeti 01 January 2013 (has links) (PDF) The current generation wind turbines are upscaled into multi megawatt range in terms of output power. However, the energy benefit from the turbine is offset by the increased mass and cost. Twenty MW wind turbines are now feasible with rotor diameters up to 200 m, according to a new report from the EU-funded UpWind project in 2011. The question is, how much bigger can wind turbines get realistically? One concept worth considering, and the one that is the subject of this thesis, is to have more than one rotor on a single support structure. Such turbines could have a greater power to weight ratio. Multi-rotor systems also offer the advantage of standardization, transportation and ease of installation and maintenance. In this thesis the NREL 5 MW single rotor baseline wind turbine is compared with a 5 MW multi-rotor wind turbine. The multiple rotors are downscaled using scaling curves keeping the 5 MW baseline machine as reference. Multi-Rotor Wind Turbine Design Cost Scaling Analysis Computer-Aided Engineering and Design Energy Systems Other Engineering Other Mechanical Engineering Structural Engineering
13	DRONAR: Obstacle echolocation using ego-noise / DRONAR: Egenljudsekolokalisering av hinder Nilsson, Henrik January 2023 (has links) You do not want your drone to crash. Therefore, safety systems should be put in place to prevent such an event, and obstacle avoidance is a major part of this. Today, the most successful techniques use cameras or light detection and ranging (LIDAR) to find and avoid obstacles; but to improve resiliency, multiple systems should be used. This thesis proposes to use microphones, listening to the drone’s own noise, to estimate the distance to surrounding obstacles. An obstacle echolocation solution for multi-rotor aerial vehicles (MAVs) using ego-noise is developed. The MAV’s noise is captured and auto-correlated to detect echoes at different time delays. This signal is whitened to remove structured measurement noise resulting from the narrow-band components of the MAV’s noise. By recording the MAV’s noise using multiple microphones, a time of arrival (TOA) estimate of the obstacle position is achieved. A beamforming-based solution is used to calculate this estimate. A series of simplified proof-of-concept experiments show that ego-noise echolocation is possible and that the developed solution works in a controlled environment. A prototype implementation of a realistic system is also created. Four signal fusion alternatives are compared, though no best alternative is found for all situations. More work is needed to apply the findings of this work in a robust way, but the principle is shown to work. Drone Autonomous systems Obstacle avoidance Sound Noise Planning SONAR Ego-noise Multi-rotor aerial vehicle Unmanned areal vehicle Drönare Autonoma system Hinderundvikning Ljud Oljud Planering SONAR Egenljud Multirotorfordon Obemannat luftfordon Signal Processing Signalbehandling Computer Systems Datorsystem Robotics Robotteknik och automation Control Engineering Reglerteknik

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