Search for dissertations about: "flow-separation control"

Showing result 1 - 5 of 11 swedish dissertations containing the words flow-separation control.

  2. 1. Wings, turbulent boundary layers and flow separation

    Author : Fermin Mallor; Philipp Schlatter; Ricardo Vinuesa; Ramis Örlü; Manuel García Villalba; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wings; turbulent boundary layers; adverse pressure gradients; flow separation; numerical simulations; wind-tunnel experiments; flow control.; Vingar; turbulenta gränsskikt; negativa tryckgradienter; avlösning; numeriska simuleringar; vindtunnel-experiment; flow control; Aerospace Engineering; Flyg- och rymdteknik; Teknisk mekanik; Engineering Mechanics;

    Abstract : The present doctoral thesis investigates the turbulent flow developing around wing sections, focusing on the impact of adverse-pressure-gradient (APG) conditions on turbulent boundary layers (TBLs) and the physics of flow separation. Both experimental and numerical methods are employed to generate high-fidelity data sets and provide an in-depth analysis of the flow. READ MORE

  4. 2. 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

  5. 3. Computational fluid-dynamics investigations of vortex generators for flow-separation control

    Author : Florian von Stillfried; Arne Johansson; Stefan Wallin; Jonathan Morrison; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow-separation control; vane vortex generator; vortex generator jet; zero-pressure-gradient turbulent boundary layer; adverse-pressure-gradient turbulent boundary layer; statistical modelling; turbulence; Reynolds stress- transport model; computational fluid dynamics;

    Abstract : Many flow cases in fluid dynamics face undesirable flow separation due to ad-verse pressure gradients on wall boundaries. This occurs, for example, due togeometrical reasons as in a highly curved turbine-inlet duct or on flow-controlsurfaces such as wing trailing-edge flaps within a certain angle-of-attack range. READ MORE

  6. 4. 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

  7. 5. Experimental Study on Truck Related Power Losses: The Churning Losses in a Transmission Model and Active Flow Control at an A-pillar of Generic Truck Cabin Model

    Author : Erwin Adi Hartono; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot wire anemometry; Machine learning; Computational Fluid Dynamics; A-Pillar; Transmission; Flow separation; Churning losses; CFD; Gearbox; Torque measurement; Particle Image Velocimetry; Smoothed Particle Hydrodynamics.; Active Flow Control; SPH; Curve fit; Synthetic Jets; Load independent power losses; Aeration; Flow visu- alization;

    Abstract : The fight with global warming constantly forces vehicle manufacturers to innovate, in order to be able to reduce the CO2 emissions of their product. This means that marginal efficiency gains in every component are considered beneficial for total reduction of CO2 emissions. READ MORE