Sökning: "rotor dynamics"

Visar resultat 21 - 25 av 50 uppsatser innehållade orden rotor dynamics.

  1. 21. Evolution of Cavity Tip Vortices in High-Pressure Turbines

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Elektricitetslära

    Författare :Albin Berglund; [2017]
    Nyckelord :CFD; turbomachinery; tip gap; fluid dynamics; cavity; rotor blade;

    Sammanfattning : This degree project in applied physics studies the tip gap flows over the rotor blades of a high-pressure turbine. The rotor blade used in the study has an improved design that utilizes both a cavity tip and an uneven profiling to reduce turbine loss. LÄS MER

  3. 22. Dynamics and electronics of a manually chargeable quadcopter for steady-state flight

    M1-uppsats, Mälardalens högskola/Akademin för innovation, design och teknik

    Författare :Ioannis Kantsaporidis; Sadeq Al-Attar; [2017]
    Nyckelord :Rechargeable quadcopter; back emf; momentum theory; sustainability; battery performance; thrust; power;

    Sammanfattning : The objective of this thesis is to investigate how the onboard battery of a quadcopter can be charged through manual rotation of its motors, while understanding the resulting aerodynamical forces acting on the rotors during hover, as well as considering the changes in thrust capabilities when the electronic and structural design are altered. A theoretical approach using the momentum theory will present a general understanding of rotor performance whilst describing the correlation between rotor parameters, thrust and mechanical power. LÄS MER

  4. 23. Aerodynamic performance of a wind-turbine rotor by means of OpenFOAM

    Master-uppsats, KTH/Mekanik

    Författare :Evangelos Giannopoulos; [2017]
    Nyckelord :wind turbine; rotor; performance; CFD model; boundary layer; roughness;

    Sammanfattning : In order for wind-farm operators to deal with challenges regarding their fleet management, it is useful for them to estimate their units’ performance for different conditions. To perform such estimations, Computational Fluid Dynamics (CFD) may be used. LÄS MER

  5. 24. Identification and Estimation of DC-Motor Dynamics for the Crazyflie Quadcopter

    Uppsats för yrkesexamina på avancerad nivå, Lunds universitet/Institutionen för reglerteknik

    Författare :Erik Ottosson; [2017]
    Nyckelord :Technology and Engineering;

    Sammanfattning : In this thesis methods for finding state space representation parameters for low inductance DC-motors are found and evaluated. Theory previously tested in simulations is verified experimentally and improved upon for both linear behaviour when the motor is controlled with a DC-source as well as nonlinear behaviour when controlled with pulse width modulation (PWM). LÄS MER

  7. 25. An Alternative Variable Valve Timing System for Heavy Duty Vehicles

    Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/Institutionen för teknikvetenskap och matematik

    Författare :Mikael Eriksson; Daniel Olovsson; [2016]
    Nyckelord :Variable; Valve Timing; VVT; Cam phaser; Heavy Duty; Scania; Commercial Vehicles; GT-SUITE; Dynamic; On off valve; Product Development; Machine Element;

    Sammanfattning : The ability to control engine valve timing has the potential to alter the engine performance over the entire operating range. The outcome of valve timing technology enables the possibility to increase efficiency, lowering emissions, increase engine torque, etc. One of the simplest ways to obtain a variable valve timing is to use cam phasers. LÄS MER