Sökning: "Turbulent Boundary Layer"

Visar resultat 1 - 5 av 43 uppsatser innehållade orden Turbulent Boundary Layer.

  1. 1. On intermittency in the turbulent asymptotic suction boundary layer

    Master-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Edoardo Foschi; [2023]
    Nyckelord :Turbulence; turbulent boundary layer; intermittency; numerical simulation; DNS; tripping; suction;

    Sammanfattning : This thesis presents a series of direct numerical simulations (DNS) performed in order to understand the discrepancy in the literature regarding turbulent asymptotic suction boundary layers (TASBLs) at low Reynolds numbers. The hypothesis to be tested is that the main reason for higher turbulence intensities observed in experiments compared to DNS is that the latter exhibits intermittent patches of laminar flow, developing both temporally and spatially. LÄS MER

  3. 2. Turbulent Boundary Layers Modelling with Deep Operator Networks

    Master-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Yu-Cheng Lu; [2023]
    Nyckelord :Turbulent Boundary Layers; Pressure Gradient; Composite Profiles; Deep Operator Networks; Sensitivity Analysis Nyckelord på svenska;

    Sammanfattning : This thesis project aims to advance the modelling of pressure gradient turbulent boundary layers (PG TBLs) and offer new insights into TBLs modelling. Previous analytical studies have explored various mathematical models, but this research introduces an extended unstacked Deep Operator Networks (DeepONets) architecture with double outputs and five branch parameters. LÄS MER

  4. 3. Development of HVAC simulations for truck cabins using OpenFOAM

    Master-uppsats, Linköpings universitet/Mekanisk värmeteori och strömningslära

    Författare :Junaid Haider; [2023]
    Nyckelord :Computational Fluid Dynamics; OpenFOAM; Conjugate Heat Transfer; chtMultiRegionFoam;

    Sammanfattning : In regions with cold climates, a layer of ice often forms on vehicle windshields, whichobstructs the driver’s view. To address this issue, vehicles are equipped with internal defrosters. However, at Scania, the evaluation of defroster design performancecurrently relies on time-consuming and costly physical testing. LÄS MER

  5. 4. Active flow control of the turbulent boundary layer over a NACA4412 wing profile for skin friction drag reduction

    Master-uppsats, KTH/Teknisk mekanik

    Författare :Giacomo Semprini Cesari; [2023]
    Nyckelord :Active flow control; drag reduction; numerical simulations; turbulent boundary layer; wings;

    Sammanfattning : In the context of building a framework for active flow control of turbulent boundary layers in wings, a set of large-eddy simulation (LES) are implemented in OpenFOAM. The flow around a NACA4412 wing profile is simulated at 5° angle of attack and Re_c = 400˙000. LÄS MER

  7. 5. Design of compact automotive heat exchanger, analysing the effects of RANS models and utilising Additive Manufacturing

    Kandidat-uppsats, KTH/Fysik

    Författare :Nikhil Srikkanth; Bartosz Brzuchalski; [2022]
    Nyckelord :Turbulence; Reynolds Averaged Navier-Stokes; KTH Formula Student; metal additive manufacturing; CFD; turbulent kinetic energy; boundary layer;

    Sammanfattning : The analytical modelling of complex turbulent airflow remains one of the great unsolved mysteries of physics, but in this paper two widely used Reynolds Averaged Navier-Stokes models (k-$\epsilon$ and k-$\omega$ SST) are compared while designing a heat exchanger for the KTH Formula Student electric race car. CAD software was used to design lattices for the heat exchanger core and theorise about how to increase heat transfer while also taking into account the utilisation of metal additive manufacturing. LÄS MER