Sökning: "Unsteady"

Visar resultat 6 - 10 av 176 avhandlingar innehållade ordet Unsteady.

  1. 6. Accurate physical and numerical modeling of complex vortex phenomena over delta wings

    Författare :Simone Crippa; Arthur Rizzi; Stefan Wallin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; computational fluid dynamics; CFD; vortical flow; delta wing; aerodynamics; flow physics; steady; unsteady; Vehicle engineering; Farkostteknik;

    Sammanfattning : With this contribution to the AVT-113/VFE-2 task group it was possible to prove the feasibility of high Reynolds number CFD computations to resolve and thus better understand the peculiar dual vortex system encountered on the VFE-2 blunt leading edge delta wing. Initial investigations into this phenomenon seemed to undermine the hypothesis, that the formation of the inner vortex system relies on the laminar state of the boundary layer at separation onset. LÄS MER

  3. 7. Numerical simulation of viscous compressible flows applied to turbomachinery blade flutter

    Författare :L. D. Gunnar Sidén; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; unsteady; flutter; turbine; aeroengine; turbomachinery; numerical method; oscillating; Navier-Stokes; finite volume; viscious; finite element; turbulent; fan; aeroelastic; vibration; compressor; stall;

    Sammanfattning : .... LÄS MER

  4. 8. Numerical computations of the unsteady flow in turbochargers

    Författare :Fredrik Hellström; Laszlo Fuchs; Ricardo Martinez-Botas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbochargers; turbine; compressor; unsteady pulsatile flow; perturbations; Large Eddy Simulation; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Turbocharging the internal combustion (IC) engine is a common technique to increase the power density. If turbocharging is used with the downsizing technique, the fuel consumption and pollution of green house gases can be decreased. LÄS MER

  5. 9. Numerical and Experimental study of shock boundary layer interaction in unsteady transonic flow

    Författare :Olivier Bron; KTH; []
    Nyckelord :Shock Boundary Layer Interaction; Shock Motion; Unsteady Flows; Nozzle Flows; Potential Interaction; Back Pressure Perturbations;

    Sammanfattning : A prerequisite for aeroelastic stability prediction inturbomachines is the understanding of the fluctuatingaerodynamic forces acting on the blades. Unsteady transonicflows are complex because of mutual interactions betweentravelling pressure waves, outlet disturbances, shock motion,and fluctuating turbulent boundary layers. LÄS MER

  7. 10. Modelling of unsteady aerodynamics for aircraft design

    Författare :Christopher Jouannet; Linköpings universitet; []
    Nyckelord :Aircraft Deisgn; Aerodynamic; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis present a simple mathematical prediction model for high angles of attack aerodynamics, including dynamic effects over delta wings, and an extension to full configuration. The model presented is intended for application in conceptual design and is extended to parameters identifications in preliminary design with validation against experimental data. LÄS MER