Sökning: "square cylinder"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden square cylinder.

  1. 1. Numerical Study of Laminar, Transitional and Turbulent Flow Past Rectangular Cylinders

    Författare :Ahmad Sohankar Esfahani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; blockage; outlet boundary condition; rectangular cylinders; onset of vortex shedding; angle of incidence; incompressible flow; LES; DNS; transition; finite volumes; Reynolds number; numerical simulation; square cylinder;

    Sammanfattning : The subject of flow past slender bluff bodies is of relevance to technical problems associated with energy conservation, structural design and acoustic emissions. The present work is restricted to an important sub-class of slender bluff body flow --- the incompressible flow around a stationary cylinder having a rectangular cross section, the cylinder being exposed to a constant free stream velocity. LÄS MER

  3. 2. Turbulence Measurements in a Natural Convection Boundary Layer and a Swirling Jet

    Författare :Abolfazl Shiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swirl; constant current bridge; high Rayleigh number; natural convection; Jet; cold-wire thermometry; vertical cylinder; laser Doppler anemometry; turbulent boundary layers;

    Sammanfattning : Two sets of experimental measurement were carried out on an axisymmetric swirling jet flow and a natural convection boundary layer. In the first experiment, the far field of an incompressible swirling jet, discharged into a quiescent ambient has been studied using laser Doppler anemometry. LÄS MER

  4. 3. Studies on the Load Range of an HCCI Engine using In-Cylinder Pressure, Ion Current and Optical Diagnostics

    Författare :Andreas Vressner; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ion current; knock; laser ignition; chemiluminescence imaging; LES; temperature stratification; PLIF; auto igntion; flame propagation; HCCI; diagnostics; low temperature combustion;

    Sammanfattning : Internal combustion engines are continuously developed towards decreased hazardous emissions and lower fuel consumption. The homogeneous charge compression ignition (HCCI) engine is a promising concept which combines the best features of the Diesel engine and the spark ignition (SI) engine. LÄS MER

  5. 4. A study of heat transfer from cylinders in turbulent flows by using thermochromic liquid crystals

    Författare :Roland Wiberg; KTH; []
    Nyckelord :Fluid mechanics; convection heat transfer;

    Sammanfattning : In gas quenching, metal parts are rapidly cooled from hightemperatures, and the convection heat transfer coefficientdistributions are of importance for the hardness and thedistortion (the shape nonuniformities) of the quenched parts.Thermochromic liquid crystals (TLC) and a thin foil techniques,were investi- gated and used for studies of a circular cylinderin axial flows, affected and not affected by upstream owmodifying inserts. LÄS MER

  7. 5. Cost Optimization of Volumetric Surveillance for Sky Monitoring : Towards Flying Object Detection and Positioning

    Författare :Hiba Alqaysi; Mattias O'Nils; Najeem Lawal; Faisal Qureshi; Fabio Poiesi; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; image processing; deep learning; YOLOv4; smart cameras;

    Sammanfattning : Unlike surface surveillance, volumetric monitoring deals with three-dimensional target space and moving objects within it. In sky monitoring, objects fly within outdoor and often remote volumes, such as wind farms and airport runways. Therefore, multiple cameras should be implemented to monitor these volumes and analyze flying activities. LÄS MER