Sökning: "boundary layer flow"

Visar resultat 1 - 5 av 64 uppsatser innehållade orden boundary layer flow.

  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. Acoustic Characterization of Catalyst

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

    Författare :Surachit Dokson; [2023]
    Nyckelord :;

    Sammanfattning : The WHO has set a sound level threshold of 55 dB, beyond which noise is considered harmful to humans when exposed for an extended period of time. It is, however, estimated by the European Environmental Agency that over 110 million people in the EU are regularly exposed to levels of traffic noise above 55 dB. 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. Verification and validation of the implementation of an Algebraic Reynolds-Stress Model for stratified boundary layers

    Master-uppsats, KTH/Teknisk mekanik

    Författare :Martina Formichetti; [2022]
    Nyckelord :Atmospheric boundary layer; turbulence modelling; stratified flows; eddy viscosity; eddy diffusivity;

    Sammanfattning : This thesis studies the implementation of an Explicit Algebraic Reynolds-Stress Model(EARSM) for Atmospheric Boundary Layer (ABL) in an open source ComputationalFluid Dynamics (CFD) software, OpenFOAM, following the guidance provided by thewind company ENERCON that aims to make use of this novel model to improvesites’ wind-field predictions. After carefully implementing the model in OpenFOAM,the EARSM implementation is verified and validated by testing it with a stratifiedCouette flow case. LÄS MER