Sökning: "domain wall boundary conditions"

Visar resultat 6 - 10 av 14 avhandlingar innehållade orden domain wall boundary conditions.

  1. 6. Modelling Techniques for Large-Eddy Simulation of Wall-Bounded Turbulent Flows

    Författare :Timofey Mukha; Mattias Liefvendahl; Hrvoje Jasak; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wall modelling; Inflow generation; Large-eddy simulation; OpenFOAM; Computational fluid dynamics; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Large-eddy simulation (LES) is a highly accurate turbulence modelling approach in which a wide range of spatial and temporal scales of the flow are resolved. However, LES becomes prohibitively computationally expensive when applied to wall-bounded flows at high Reynolds numbers, which are typical of many industrial applications. LÄS MER

  3. 7. Coherent structures and control in wall-bounded turbulent flows

    Författare :Marco Atzori; Philipp Schlatter; Ricardo Vinuesa; Oscar Flores; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent boundary layers; numerical simulations; coherent structures; predetermined flow control.; Turbulenta gränsskikt; numeriska simuleringar; koherenta strukturer; förutbestämd flödeskontroll; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : This thesis is concerned with two distinct topics related to the study of wall-bounded turbulence: the connection between instantaneous three-dimensional coherent structures and mean-flow properties, and the development and analysis of pre-determined control techniques for adverse-pressure-gradient boundary layers.We examined regions with intense velocity fluctuations in various flowcases. LÄS MER

  4. 8. Study of adverse-pressure-gradient effects on a flat-plate boundary layer at high Reynolds numbers

    Författare :Ramón Pozuelo; Ricardo Vinuesa; Philipp Schlatter; Ivette Rodriguez; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; simulations; turbulent boundary layers; adverse pressure gradients.; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : Turbulent boundary layers are present in many aspects of life, from the weather and wind currents to transportation, production of energy or mixing processes. Understanding turbulent motions can allow for an improvement and development of technical devices, techniques or diagnosis of phenomena where a fluid flow is in the turbulent regime. LÄS MER

  5. 9. High order summation-by-parts based approximations for discontinuous and nonlinear problems

    Författare :Cristina La Cognata; Jan Nordström; Sara Zahedi; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Numerical approximations using high order finite differences on summation-byparts (SBP) form are investigated for discontinuous and fully nonlinear systems of partial differential equations. Stability and conservation properties of the approximations are obtained through a weak imposition of interface and boundary conditions with the simultaneous-approximation-term (SAT) technique. LÄS MER

  7. 10. Finite Element Analysis of Structure-acoustic Systems : Methods and Applications

    Författare :Peter Davidsson; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Paper 1The problem in which a flexible structure interacts with an acoustic fluid is analysed by use of the finite element method. With increasing complexity of the geometry and when increasing the frequency limit is of interest, the number of degrees of freedom needed to describe the system becomes very large. LÄS MER