Sökning: "Fluid intake"

Visar resultat 21 - 25 av 72 avhandlingar innehållade orden Fluid intake.

  1. 21. Large Eddy Simulation of Turbulent Reactive Flows under HCCI Engine Conditions

    Författare :Tobias Joelsson; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Large Eddy Simulation (LES) modeling is developed to study homogeneous charge compression ignition (HCCI) combustion under different engine operation and mixture conditions, including real engine configurations and generic test cases. A previously developed HCCI model has been validated by comparing the simulation results with engine experiments. LÄS MER

  3. 22. Assessment and Some Improvements of Hybrid RANS-LES Methods

    Författare :Sebastian Arvidson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; hybrid RANS-LES; zonal RANS-LES; embedded LES; PDH-LRN; log-layer mismatch; LES length scale; shock boundary-layer interaction;

    Sammanfattning : Motivated by numerical analysis of a shock/boundary-layer interacting (SBLI) flow in a duct, where some typical existing hybrid RANS-LES methods become awkward to give accurate predictions of the shock-induced corner separation bubble, a new hybrid RANS-LES method, has been proposed. The model is based on a low-Reynolds-number (LRN) $k-\omega$ RANS model, which is one of the few models that are capable of giving reasonable predictions for the SBLI flow in RANS computations. LÄS MER

  4. 23. Optimal damping and slow sound in ducts

    Författare :Zhe Zhang; Mats Åbom; Hans Bodén; Lars Enghardt; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : The thesis is dedicated to expanding knowledge on two duct acoustic issues including: 1) the optimal damping of low frequency sound and 2) the development and application of ‘slow sound’.To address the first issue, the ‘Cremer impedance’ proposed more than half a century ago has been revisited and further developed. LÄS MER

  5. 24. Simulations of compressible flows associatedwith internal combustion engines

    Författare :Olle Bodin; Laszlo Fuchs; Mihai Mihaescu; Michael Leschziner; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; Gas exhange; exhaust port; exhaust manifold; POD; DMD; exhaust; LES; Gasväxling; avgasport; avgasgrenrör; POD; DMD;

    Sammanfattning : Vehicles with internal combustion (IC) engines fueled by hydrocarbon compoundshave been used for more than 100 years for ground transportation.During these years and in particular the last decade, the environmental aspectsof IC engines have become a major political and research topic. LÄS MER

  7. 25. Variable Valve Actuation in a Spark Ignition Engine - A Flow Field and Heat Release Study

    Författare :Fredrik Söderberg; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Gases; plasma; fluid dynamics; plasmas; Gaser; fluiddynamik; vakuumteknik; vibrationer; akustik; Motors and propulsion systems; Motorer; hydraulik; Maskinteknik; vibration and acoustic engineering; Laser Doppler Velocimetry Particle Image Velocimetry PIV LDV Wavelet Computational Fluid Dynamics CFD Variable Valve Actuation Timing Turbulence Combustion Engine Spark Ignition Miller; hydraulics; vacuum technology; Mechanical engineering;

    Sammanfattning : The objective of this thesis was to find ways of improving part-load efficiency for a spark ignition engine by studying the effects of variable-valve actuation on fluid flow and combustion. The in-cylinder flow was measured with laser doppler velocimetry, LDV, and particle image velocimetry, PIV. LÄS MER