Sökning: "wave plate"

Visar resultat 1 - 5 av 22 uppsatser innehållade orden wave plate.

  1. 1. Measuring the Pulse Duration and the Time-Dependent Polarisation State of Ultrashort Laser Pulses with the D-Scan Technique

    Master-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Atomfysik

    Författare :Daniel Díaz Rivas; [2022]
    Nyckelord :pulse characterisation; ultrashort; laser; femtosecond; dispersion scan; polarisation; wave plate; temporal reconstruction; electric field reconstruction; time-dependent polarisation; polarisation gate; Physics and Astronomy;

    Sammanfattning : Ultrashort laser pulses with time-dependent polarisation states have many applications, such as the generation of isolated attosecond pulses and the study of the optical chirality of molecules. In this project the polarisation gate, built from two quarter-wave plates of different orders, is thoroughly characterised in experiment and simulation. LÄS MER

  3. 2. Development of a CFD Boundary Condition to Simulate a Perforated Surface

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Medet Kiflemariam; [2021]
    Nyckelord :Computational Fluid Dynamics; CFD; Boundary Condition; Bleed; Aerospace Engineering; Aeronautical Engineering; Physics;

    Sammanfattning : In aircraft with jet propulsion engine intakes at supersonic speed, strong pressure waves referred to as shockwaves occur, which may interact with any present boundary layers along the intake surface. The adverse pressure gradients associated with Shock Wave-Boundary Layer Interaction (SWBLI) may cause boundary layer flow separation, which can result in disturbances of the flow that can be harmful to the device or decrease engine performance. LÄS MER

  4. 3. Model Design for Further Spray Deflector investigation

    Master-uppsats, KTH/Marina system

    Författare :Xinguo Wang; [2021]
    Nyckelord :High-Speed Craft; Model Design; Spray Deflector; Höghastighetshantverk; modelldesign; spraydeflektor;

    Sammanfattning : Planing hull is one solution to break the speed barrier of conventional hull, but as the boat reaches a high speed, massive whisker spray will be developed and attached to the hull, which causes a notable resistance increase. A Swedish company Peterstep invented an innovative spray deflector that can deflect the spray backwards and harvest kinetic energy from the spray. LÄS MER

  5. 4. Millimeter-Wave Pencil Beam Leaky-Wave Antenna

    Kandidat-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Tom Eriksson; Erik Westberg; [2021]
    Nyckelord :Leaky-wave antenna LWA ; Continuous transverse stubs CTS ; Parallel plate waveguide PPW ; Dispersion;

    Sammanfattning : Moving into higher frequencies, in occurrence withmodern applications, poses the issue of higher attenuation ofelectromagnetic waves, which in turn demand more directiveantennas. This paper proposes a directive antenna designoperating at 30GHz based on leaky-wave technology. Themodel consists of two main components. LÄS MER

  7. 5. Two-dimensional roughness and Tollmien-Schlichting waves: a study on transition

    Master-uppsats, KTH/Strömningsmekanik och Teknisk Akustik

    Författare :Derek Micheletto; [2020]
    Nyckelord :;

    Sammanfattning : Two-dimensional (2D) roughnesses induce premature transition to turbulence in laminar boundary layers by amplifying the disturbances in the flow and promoting the development of non-linearities. The present thesis aims at furthering our understanding of this phenomenon's underlying mechanisms and elucidating the effects of the different geometrical parameters of the roughness' cross section. LÄS MER