Search for dissertations about: "unsteady flow"

Showing result 1 - 5 of 152 swedish dissertations containing the words unsteady flow.

  2. 1. Flow measurements related to gas exchange applications

    Author : Fredrik Laurantzon; Henrik Alfredsson; Venkatesa Vasanta Ram; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow meters; vortex flow meters; compressible flow; pulsating flow; hot-wire anemometry; cold-wire anemometry; time resolved measurements; wavelet analysis;

    Abstract : This thesis deals with flow measuring techniques applied to steady and pulsating gas flows relevant to gas exchange systems for internal combustion engines. Gas flows in such environments are complex, i.e. they are inhomogeneous, three-dimensional, unsteady, non-isothermal and exhibit significant density changes. READ MORE

  4. 2. Unsteady Numerical Simulations of Flow around Heavy Vehicles, Trains and Passenger Cars

    Author : Jan Östh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large Eddy Simulation; fluid dynamics; bluff body flows; flow structures; vehicle aerodynamics; flow control; flow physics; truck aerodynamics; train aerodynamics; car aerodynamics;

    Abstract : In this thesis several simulations have been carried out aimed at improving the knowledgeof vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Four flows around different simplified vehicles have been considered. READ MORE

  5. 3. Modeling Unsteady flow Effects in 3D Throughflow Calculations

    Author : Magnus Stridh; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughflow; turbomachinery; mixing-plane; rotor-stator interaction; cascade; Deterministic stress terms; Linear harmonic; compressor; preconditioned GMRES; Unsteady; linear Navier-Stokes; turbine;

    Abstract : The flow field in a transonic multistage compressor is compressible, three-dimensional and highly unsteady and can be predicted in principle by the exact time-accurate Navier-Stokes equations. The high Reynolds number encountered in multistage turbomachinery together with the wall-bounded nature of the flow environment however prevent the use of DNS to solve the exact N-S equations. READ MORE

  6. 4. Numerical Studies of Flow and AssociatedLosses in the Exhaust Port of a Diesel Engine

    Author : Yue Wang; Laszlo Fuchs; Mihai Mihaescu; Angelo Onorati; KTH; []
    Keywords : Internal Combustion Engine; Exhaust flow; Exhaust Valve; Exhaust Port; Large Eddy Simulation; Valve and Piston Motion; Total Pressure Losses; Energy Losses; Discharge coefficient; Flow Losses; Flow structures; Air Flow Bench; Engine-like Conditions; SRA - Energy; SRA - Energi;

    Abstract : In the last decades, the focus of internal combustion engine development has moved towards more efficient and less pollutant engines. In a Diesel engine, approximately 30-40% of the energy provided by combustion is lost through the exhaust gases. The exhaust gases are hot and therefore rich of energy. READ MORE

  7. 5. Numerical computations of the unsteady flow in a radial turbine

    Author : Fredrik Hellström; Laszlo Fuchs; Jonas Bredberg; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pulsatile flow; radial turbines; pipe flow; effects of inlet conditions; Fluid mechanics; Strömningsmekanik;

    Abstract : Non-pulsatile and pulsatile flow in bent pipes and radial turbine has been assessed with numerical simulations. The flow field in a single bent pipe has been computed with different turbulence modelling approaches. READ MORE