Search for dissertations about: "passive flow control"

Showing result 1 - 5 of 48 swedish dissertations containing the words passive flow control.

  2. 1. Turbulent Boundary Layer Separation and Control

    Author : Ola Lögdberg; P. Henrik Alfredsson; Jens Fransson; Guido Buresti; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; adverse pressure gradient APG ; flow separation; vortex generators; jet vortex generators; pulsed jet vortex generators; Fluid mechanics; Strömningsmekanik;

    Abstract : Boundary layer separation is an unwanted phenomenon in most technical applications, as for instance on airplane wings, ground vehicles and in internal flow systems. If separation occurs, it causes loss of lift, higher drag and energy losses. It is thus essential to develop methods to eliminate or delay separation. READ MORE

  4. 2. Nature-inspired passive flow control using various coatings and appendages

    Author : Ugis Lacis; Shervin Bagheri; Christophe Eloy; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow control; passive appendage; surface coating; pressure drag; friction drag; Flödeskontroll; passiva bihang; ytbeläggning; tryckmotstånd; friktionsmotstånd;

    Abstract : There is a wide variety of tails, fins, scales, riblets and surface coatings, which are used by motile animals in nature. Since organisms currently living on earth have gone through millions of years of evolution, one can expect that their design is optimal for their tasks, including locomotion. READ MORE

  5. 3. Computational studies of passive vortex generators for flow control

    Author : Florian von Stillfried; Arne Johansson; Stefan Wallin; Sinisa Krajnovic; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; passive flow control; vortex generator; statistical modelling; turbulence; separation prevention; flat plate; diffuser; high-lift design; airfoil; Fluid mechanics; Strömningsmekanik;

    Abstract : Many flow cases in fluid dynamics face undesirable flow separation due torising static pressure on wall boundaries. This occurs e.g. due to geometry as ina highly curved turbine inlet duct or e. READ MORE

  6. 4. Supersonic flow separation with application to rocket engine nozzles

    Author : Jan Östlund; KTH; []
    Keywords : turbulent; boundary layer; shock wave; interaction; overexpanded; rocket nozzle; flow separation; control; side-load; experiments; models; review;

    Abstract : The increasing demand for higher performance in rocketlaunchers promotes the development of nozzles with higherperformance, which basically is achieved by increasing theexpansion ratio. However, this may lead to flow separation andensuing instationary, asymmetric forces, so-called side-loads,which may present life-limiting constraints on both the nozzleitself and other engine components. READ MORE

  7. 5. Active Flow Control for Aircrafts and Heavy Vehicles

    Author : Mohammad El-Alti; Chalmers tekniska högskola; []
    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