Sökning: "Tip vortex"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden Tip vortex.

1. 1. Wind turbine wakes : controland vortex shedding

   Författare :Davide Medici; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Energy; Power Optimisation; Active Control; Yaw; Vortex; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : Wind tunnel studies of the wake behind a model wind turbine have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry as well as particle image velocimetry (PIV) have been used to map the flow field. LÄS MER

3. 2. Wakes behind wind turbines - Studies on tip vortex evolution and stability

   Författare :Ylva Odemark; Jens Fransson; Jens Madsen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind power; aerodynamics; hot-wire anemometry; vortex dynamics;

   Sammanfattning : The increased fatigue loads and decreased power output of a wind turbine placed in the wake of another turbine is a well-known problem when building new wind power farms. In order to better estimate the total power output of a wind power farm, knowledge about the development and stability of wind turbine wakes is crucial. LÄS MER

4. 3. Computational Modelling for Cavitation and Tip Vortex Flows

   Författare :Abolfazl Asnaghi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cavitation; SST k − ω; OpenFOAM; Propeller; LES; Numerical simulation; Cur- vature correction; Elliptical foil; Inception; Twisted Delft foil;

   Sammanfattning : Cavitation often brings negative effects, such as performance degradation, noise, vibration, and material damage, to marine propulsion systems, but for optimum performance, cavitation is almost inevitable. Therefore, it is necessary to better understand cavitation in order to maximize the performance without encounter- ing severe problems. LÄS MER

5. 4. On the Aerodynamic Design of the Boxprop

   Författare :Alexandre Capitao Patrao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Open Rotors; Wake Analysis Method; Propeller Design; Propellers; CROR; Optimization; Tip vortex; Propfans;

   Sammanfattning : Economic factors and environmental awareness are driving the evolution of aircraft engines towards increasingly lower fuel consumption and emissions. The Counter-Rotating Open Rotor (CROR) is actively being researched around the world, promising a significantly increased propulsion efficiency relative to existing turbofans by employing two, unducted, counter-rotating propeller blade rows, thereby increasing the bypass ratio of the engine and decreasing nacelle drag. LÄS MER

7. 5. Simulation and Analysis of a Novel Open Rotor Propeller - the Boxprop

   Författare :Alexandre Capitao Patrao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wake Analysis Method; CFD; Open Rotors; Propfans; Tip vortex; CROR; Propellers;

   Sammanfattning : Economic factors and environmental awareness is driving the evolution of aircraft engines towards increasingly higher efficiencies, reaching for lower fuel consumption and lower emissions. The Counter-Rotating Open Rotor (CROR) is actively being researched around the world, promising a significantly increased propulsion efficiency relative to existing turbofans by employing two, counter-rotating propeller blade rows, thereby increasing the bypass ratio of the engine. LÄS MER