Sökning: "body-force model"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden body-force model.

  1. 1. Numerical computation of ship stern/propeller flow

    Författare :Daohua Zhang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lifting-line theory; Body-fitted coordinate system; viscous flow; Reynolds-Avraged NAvier-Stokes equations; stern flow; propeller; turbulence model; grid generation; propeller-hull interaction; body-force; numerical calculation;

    Sammanfattning : .... LÄS MER

  3. 2. On Multistage Analysis of Transonic Compressors: From Axisymmetric Throughflow Time-Marching to Unsteady Three-Dimensional Methods

    Författare :Stephane Baralon; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; shock; time-marching; deterministic; average-passage; multistage; fan; axisymmetric; 3D; unsteady; transonic; viscous; body force; stress; singularity; perturbation; throughflow; mixing-plane; modelling; finite-volume;

    Sammanfattning : A throughflow time-marching finite-volume solver, capable of computing viscous transonic multistage compressor flows with embedded shocks, is presented. The behavior of the blade model, based on the blade mean surface flow tangency condition, was investigated for transonic flows. LÄS MER

  4. 3. Flow Control and Shape Optimization of Intermediate Turbine Ducts for Turbofan Engines

    Författare :Fredrik Wallin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; response surface methodology; intermediate turbine duct; vortex generators; turbine intermediate case; endwall contouring; turbine center frame; body-force model; shape optimization; mid-turbine frame; flow control;

    Sammanfattning : Demands on improved efficiency, reduced emissions and lowered noise levels cause a strive towards high by-pass ratios of commercial turbofan engines. This results in an increased radial offset between the high- and low-pressure turbines. Thus the design of the intermediate turbine duct connecting the two turbines becomes more challenging. LÄS MER

  5. 4. Aerodynamic Design and Optimization of Intermediate Ducts for High By-pass Ratio Jet Engines

    Författare :Fredrik Wallin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intermediate transition ducts; vortex generators; S-shaped ducts; response surface methodology; source term model; optimization;

    Sammanfattning : Demands on improved efficiency and reduced noise levels cause a strive toward high by-pass ratio commercial aero engines. This results in multi-spool aero engines with small high-pressure ratio cores and large fans. The low-pressure system has a lower rotational speed and a larger radius than the high-pressure core system. LÄS MER

  7. 5. Effect of drag reducing plasma actuators using LES

    Författare :Romain Futrzynski; Gunilla Efraimsson; P. Henrik Alfredsson; Emma Alenius; Johan Revstedt; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow control; drag reduction; plasma actuator; DMD; LES; optimization; pulsating flow; strömningskontroll; motståndsminskning; plasmaaktuator; DMD; LES; optimering; pulserande strömning; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The work performed in this thesis explores new ways of reducing the drag of ground vehicles. Specifically, the effect of plasma actuators are investigated numerically with the intention to delay separation around a half-cylinder, a geometry chosen to represent a simplified A-pillar of a truck. LÄS MER