Sökning: "drag"

Visar resultat 6 - 10 av 424 avhandlingar innehållade ordet drag.

1. 6. 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

3. 7. 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. 8. Passenger Car Wheel Aerodynamics

   Författare :Christoffer Landström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; tyres; wind tunnel; Passenger car aerodynamics; ground simulation; wheel rotation; drag; wheels;

   Sammanfattning : Current and future requirements for efficiency force the automotive industry to consider all aspects of reducing the energy consumption of road going vehicles. An important aspect of reducing fuel consumption is reduced aerodynamic drag, which at highway cruising speeds is dominating the total drag force for both cars and heavy goods vehicles. LÄS MER

5. 9. Aerodynamics of two trucks driving in close-proximity

   Författare :Johannes Törnell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; drag; aerodynamics; cab over engine; inter-vehicle distance; lateral offset; side wind; truck; platooning; yaw; close proximity; wake;

   Sammanfattning : There are several factors driving the development of vehicles with higher efficiency in society, chief among them are the emissions of greenhouse gases and their contribution to global warming. Therefore, there is a strong incentive to improve heavy-duty trucks' energy efficiency, supported by new legislation. LÄS MER

7. 10. Vehicle wakes in side wind

   Författare :Magnus Urquhart; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; surrogate model; optimization; CFD; wind; crossflow; drag; yaw; cavity; wake; tomographic PIV; aerodynamics;

   Sammanfattning : There is a global push to reduce the energy consumption of passenger vehicles with increasingly stringent targets and regulations. More than one-tenth of Europe's greenhouse gasses are due to passenger vehicles. The aerodynamic drag is a major contributor to energy consumption responsible for more than a quarter of the vehicle's energy usage. LÄS MER