Avancerad sökning

Visar resultat 1 - 5 av 50 uppsatser som matchar ovanstående sökkriterier.

  1. 1. Propulsion modelling of a generic submarine propeller

    Master-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Gustav Boman; [2023]
    Nyckelord :OpenFOAM; CFD; actuator line model; rotor disk; actuator disk; INSEAN E1619; propeller;

    Sammanfattning : Self propulsion modelling is important in order to accurately simulate ships and submarinesusing Computational Fluid Dynamics (CFD). However, fully resolved simulations of hull andpropeller geometries are computationally heavy and time consuming. As such there is a greatinterest in lower order CFD models of propellers. LÄS MER

  3. 2. Multibody modelling of the vibrations in an aircraft engine

    Master-uppsats, KTH/Lättkonstruktioner, marina system, flyg- och rymdteknik, rörelsemekanik

    Författare :Charly Mollet; [2022]
    Nyckelord :Vibrations; Multibody Modelling; Rolling Bearings; Rotor Dynamics; Reduction Processes; Vibrationer; multikroppsmodellering; rullingslager; rotordynamik; reducktionsprocesser;

    Sammanfattning : During the assembly of aircraft engines, some clearance is left in the rolling bearings mainly to reduce friction. However this clearance might allow the rolling element to vibrate during flight. Indeed, unwanted vibrations called non-synchronous vibrations (NSV) appear on the data recorded by the sensors on some development engines. LÄS MER

  4. 3. Polarizability and Orientation Dynamics of Small Proteins

    Master-uppsats, Uppsala universitet/Materialteori

    Författare :Ebba Koerfer; [2022]
    Nyckelord :Protein orientation; single-particle imaging; polarizability; orientation dynamics; rigid rotor model;

    Sammanfattning : Proteins often carry an intrinsic electric dipole moment, which can interact with external electric fields and cause protein motion. Previous research has found that the orientation of small proteins in gas phase can be controlled in a static electric field. LÄS MER

  5. 4. Rotor Dynamic Modeling of Hydropower Rotors by 3D-Finite Element Analysis

    Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/Institutionen för teknikvetenskap och matematik

    Författare :Simon Pääjärvi; [2022]
    Nyckelord :Rotordynamics; Applied Mechanics; Dynamics; Rotor; Finite Element Analysis; Hydropower; Solid Mechanics; Energy Production;

    Sammanfattning : By using the rotor dynamic capabilities of Simcenter Nastran Rotordynamics, an eigenvalue analysis of 3D-finite element models of the Jeffcott rotor and the overhung rotor were conducted and compared to the results with beam-based, lumped parameter models. The first two critical speeds of the Jeffcott rotor were estimated with variations of 3. LÄS MER

  7. 5. The role of location of low inertia in power systems

    Master-uppsats, Uppsala universitet/Institutionen för elektroteknik

    Författare :Bashar Alahmad; [2021]
    Nyckelord :Low inertia; Frequency stability; Rotor-angle stability; Nordic 32; Kundur; PowerFactory; Small-signal stability; Inter-area oscillation; Rate of Change of Frequency.;

    Sammanfattning : The plans to reduce the energy-related greenhouse gas emissions stimulate the deployment of electronically interfaced renewable resources. The increased penetration of such intermittent sources together with phasing conventional power plants out and the installation of High Voltage Direct Current (HVDC) links for long-distance more efficient transmission, reduces the stored inertia in any electrical grid. LÄS MER