Search for dissertations about: "drag reduction"

Showing result 1 - 5 of 40 swedish dissertations containing the words drag reduction.

  1. 1. Active Flow Control for Drag Reduction of Heavy Vehicles

    Author : Mohammad El-Alti; [2012]
    Keywords : 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;

    Abstract : 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. READ MORE

  2. 2. Vehicle wakes subject to side wind conditions

    University dissertation from Gothenburg : Chalmers tekniska högskola

    Author : Magnus Urquhart; [2019]
    Keywords : 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;

    Abstract : 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. READ MORE

  3. 3. Real Time Drag Minimization

    University dissertation from Stockholm : KTH

    Author : Marianne Jacobsen; Ulf Ringertz; Anders Forsgren; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeronautics; optimization; experimental verification; TECHNOLOGY Engineering mechanics Vehicle engineering; TEKNIKVETENSKAP Teknisk mekanik Farkostteknik;

    Abstract : 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. READ MORE

  4. 4. Active Flow Control for Aircrafts and Heavy Vehicles

    University dissertation from Stockholm : KTH

    Author : Mohammad El-Alti; [2009]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trucks; Drag reduction; Bluff-body; Large-eddy Simulation; Wake; Tilt-rotor wing; optimization; Aircrafts; Heavy vehicles; Active and Passive Flow Control; Response surface methodology; Synthetic-jet Actuator;

    Abstract : Bluff-body flows are dominated by large dissipative vortex-shedding wakes with low mean pressure compared to the high pressure on their frontal area. This induced pressure difference is the major contribution to the total aerodynamic drag. READ MORE

  5. 5. Modelling and control of turbulent and transitional flows

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Pierluigi Morra; Dan S. Henningson; Ardeshir Hanifi; André V. G. Cavalieri; Shervin Bagheri; Aimee S. Morgans; [2020]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reduced order modeling; flow control; resolvent analysis; transi- tional boundary layer; turbulent boundary layer; drag reduction; high-fidelity wall-turbulence modelling; modellreduktion; strömningskontroll; resolvent analys; laminär- turbulent omslag; turbulent gränsskikt; motståndsminskning; väggturbulens modellering; Teknisk mekanik; Engineering Mechanics;

    Abstract : The dynamics of fluid motion can accurately be described by the Navier– Stokes equations. Manipulating these equations to reduce their complexity but preserving their main characteristics has always been a key research activity in the field of fluid mechanics. READ MORE