Sökning: "PIV measurement"

Visar resultat 6 - 10 av 48 avhandlingar innehållade orden PIV measurement.

  1. 6. Laser Based Flow Measurements to Evaluate Hydraulic Conditions for Migrating Fish and Benthic Fauna

    Författare :S M Sayeed Bin Asad; Staffan Lundström; J. Gunnar I. Hellström; Anders G. Andersson; Berhanu Mulu Geberkiden; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fish Migration; Step Cylinder; Shedding; Vortex Street; Shear stress; PIV; benthic fauna; river; stones; Strömningslära; Fluid Mechanics;

    Sammanfattning : Hydropower is one of the main sources for Sweden’s energy, which is clean and renewable. It is a clean energy source because no fuels are burned which does not pollute the air and it is a renewable energy source as it only uses natural water cycle for generating energy. LÄS MER

  3. 7. Feathers by day, membranes by night - Aerodynamic performance in bird and bat flight

    Författare :Florian Muijres; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; animal flight; aerodynamics; vortex wake; actuator disk; flight performance; span efficiency; bird; bat; wind tunnel; PIV; Pied Flycatcher; Glossophaga soricina; Leptonycteris yerbabuenae;

    Sammanfattning : The efficiency and performance of a flying animal is directly related to the aerodynamics around its body and flapping wings. Here, I have developed methods for quantifying the wake dynamics around a flying animal. The results are used to estimate the aerodynamic performance of flapping flight. LÄS MER

  4. 8. In-Cylinder Fluid Flow, Fuel Preparation and Combustion in SI Engines - Application of Optical Diagnostics

    Författare :Martin Ekenberg; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laserteknik; vakuumteknik; vibrationer; akustik; Motors and propulsion systems; Motorer; hydraulik; Maskinteknik; PIV; vibration and acoustic engineering; hydraulics; vacuum technology; Mechanical engineering; framdrivningssystem; Laser technology;

    Sammanfattning : In this thesis laser-based measurements of in-cylinder flow and fuel concentrations in two stroke and direct injected four-stroke engines are presented. The major problem with the carburetted two-stroke engine is the short-circuiting of fuel that occurs during the scavenging phase. This leads to large emissions of unburned hydrocarbons. LÄS MER

  5. 9. Impacts of alternative combustion diluents and hydrogen addition on a swirl-stabilized flame related to gas turbine application

    Författare :Mao Li; Kraftverksteknik; []
    Nyckelord :lean premixed combustion; Swirl-stabilized flame; Gas turbine combustion; Flame dilution; H2 addition; Lean blowout; CO emission; PVC; CH chemiluminescence; Inverse Abel transform; PIV; POD;

    Sammanfattning : The global energy tendency leads to increasing attention on clean combustion technologies in order to eliminate adverse impacts on the environment. The utilization of oxyfuel combustion (CO2 acts as the only combustion dilution), flame diluents, and hydrogen fuel in gas turbine combustion provides a promising solution to reduce combustion pollutant emissions. LÄS MER

  7. 10. A Particle Image Velocimetry Study of Bubbly Gas-Liquid Flow

    Författare :Xiaoyun Tu; Livsmedelsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulent dispersion; Food and drink technology; Livsmedelsteknik; turbulence; Rushton turbine; stirred tank; slip velocity; bubbly gas liquid two-phase flow; coherent structure; CCD camera; PIV; POD;

    Sammanfattning : The aim of this work is to build a framework that can be used for characterizing the bubbly gas liquid turbulent flow in the stirred bioreactor tank. To this end we have developed and modified techniques with which to measure the velocity of both dispersed gas and carrier liquid phases by the optical measurement technique, a 2-CCD camera Particle Image Velocimetry (PIV) system; and to characterize the turbulence by the wavelets tool, Proper Orthogonal Decomposition (POD). LÄS MER