Sökning: "free jet"

Visar resultat 16 - 20 av 52 avhandlingar innehållade orden free jet.

  1. 16. Turbulent Shear Flow Experiments: Design of Natural Convection Rig and LDA Measurement in Swirling Jets

    Författare :Abolfazl Shiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Self-Similar Solution; Natural Convection Boundary Layer; Axisymmetric Jet; Laser Doppler Anemometry; Swirl Number;

    Sammanfattning : This work consist of two sections. In the first part, a facility has been installed and modified from an existing rig in order to measure velocity and temperature field of axisymmetric turbulent natural convection boundary layers. With using laser doppler anemometry and cold wire resistance thermometry. LÄS MER

  3. 17. Numerical studies of transtion in wall-bounded flows

    Författare :Ori Levin; Dan Henningson; Nikolaus Adams; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; suction; wall jet; streaks; waves; periodic disturbance; localized disturbance; turbulent spot; algebraic growth; exponential growth; stability; transition thresholds; transition prediction; PSE; DNS; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Disturbances introduced in wall-bounded flows can grow and lead to transition from laminar to turbulent flow. In order to reduce losses or enhance mixing in energy systems, a fundamental understanding of the flow stability and transition mechanism is important. LÄS MER

  4. 18. Some Mathematical Aspects of Thermo and Fluid Dynamics

    Författare :Carl Fredrik Stein; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; swirling jets; vortex breakdown; conical self-similarity; Long s jet; Taylor s hypothesis; frozen turbulence hypothesis; advection velocity; conjugate heat transfer; asymptotic analysis; swirling jets;

    Sammanfattning : This thesis contains mathematical treatments of three issues in thermo and fluid dynamics: swirling jets and vortex breakdown, Taylor's hypothesis and conjugate heat transfer. The work on swirling jets is focused on the study of the well-posedness of the conically self-similar free-vortex solutions to the Navier--Stokes equations. LÄS MER

  5. 19. Active Control and Modal Structures in Transitional Shear Flows

    Författare :Onofrio Semeraro; Dan Henningson; Bernd Noack; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; flat-plate boundary layer; optimal controllers; model reduction; turbulent jet; POD; DMD; Koopman modes;

    Sammanfattning : Flow control of transitional shear flows is investigated by means of numerical simulations. The attenuation of three-dimensional wavepackets of Tollmien-Schlichting (TS) and streaks in the boundary layer is obtained using active control in combination with localised sensors and actuators distributed near the rigid wall. LÄS MER

  7. 20. Ion pairing and Langmuir-like adsorption at aqueous surfaces studied by core-level spectroscopy

    Författare :Victor Ekholm; Olle Björneholm; Jan-Erik Rubensson; Markus Ammann; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; XPS; Surface; Aqueous; Liquid jet; Langmuir;

    Sammanfattning : Surface-bulk equilibria for solutes in aqueous solutions are studied using X-ray Photoelectron Spectroscopy (XPS) with high surface and chemical sensitivity. In the first part, the results show a reduction of the biochemically relevant guanidinium ions’ surface propensity with the addition of disodium sulphate due to ion pairing with the strongly hydrated sulphate ion, which could have implications for protein folding. LÄS MER