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Visar resultat 1 - 5 av 57 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Drag reduction using plasma actuators

   Författare :Romain Futrzynski; Gunilla Efraimsson; P. Henrik Alfredsson; Charles Mockett; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow control; drag reduction; plasma actuator; DMD; LES; optimization; pulsating flow; strömningskontroll; motståndsminskning; plasma ställdon; DMD; LES; optimering; pulserande flöde; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : This thesis is motivated by the application of active flow control on the cabin of trucks, thereby providing a new means of drag reduction. Particularly, the work presented strives to identify how plasma actuators can be used to reduce the drag caused by the detachment of the flow around the A-pillars. LÄS MER

3. 2. Active Flow Control for Drag Reduction of Heavy Vehicles

   Författare :Mohammad El-Alti; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active and Passive Flow Control; Tilt-rotor wing; Large-eddySimulation; Heavy vehicles; optimization; Full-scale road test; Trucks; Bluff-body; Wake; Drag reduction; Aircrafts; Response surface methodology; Synthetic-jet Actuator;

   Sammanfattning : This thesis considers the aerodynamics of trucks. The work focuses on the aerodynamic drag caused by the wake. Bluff-body flows are dominated by large dissipative vortex-shedding wakes with a low mean pressure compared to the high pressure on their frontal area. LÄS MER

4. 3. Effect of drag reducing plasma actuators using LES

   Författare :Romain Futrzynski; Gunilla Efraimsson; P. Henrik Alfredsson; Emma Alenius; Johan Revstedt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow control; drag reduction; plasma actuator; DMD; LES; optimization; pulsating flow; strömningskontroll; motståndsminskning; plasmaaktuator; DMD; LES; optimering; pulserande strömning; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The work performed in this thesis explores new ways of reducing the drag of ground vehicles. Specifically, the effect of plasma actuators are investigated numerically with the intention to delay separation around a half-cylinder, a geometry chosen to represent a simplified A-pillar of a truck. LÄS MER

5. 4. Vehicle wakes subject to side wind conditions

   Författare :Magnus Urquhart; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; drag; surrogate model; cavity; Latin Hypercube Sampling; wake; aerodynamics; real world conditions; Proper Orthogonal Decomposition; wind averaged drag; Radial Basis Functions; side wind; optimization; tapered extensions; cycle averaged;

   Sammanfattning : Passenger vehicles are associated with travel flexibility, today it is clear that this flexibility impacts the environment. Passenger vehicles account for more than one-tenth of all greenhouse gasses in Europe with approximately a quarter of the vehicle's energy consumption wasted as aerodynamic drag. LÄS MER

7. 5. Real Time Drag Minimization

   Författare :Marianne Jacobsen; Ulf Ringertz; Anders Forsgren; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeronautics; optimization; experimental verification; Vehicle engineering; Farkostteknik;

   Sammanfattning : This thesis focuses on the use of multiple redundant control surfaces to increase performance during flight. There is no clear-cut definition of performance. It may differ between applications, but here, the amount of drag for a given flight condition is used. LÄS MER