Sökning: "Numerical solution"

Visar resultat 1 - 5 av 333 uppsatser innehållade orden Numerical solution.

  1. 1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity

    Master-uppsats, KTH/Fysik

    Författare :Atabak Fathe Jalali; [2024]
    Nyckelord :Theoretical physics; astrophysics; modified gravity; minimally modified gravity; gravitational collapse; VCDM; scalar collapse; apparent horizon; numerical relativity; Teoretisk fysik; astrofysik; modifierad gravitation; minimalt modifierad gravitation; gravitationskollaps; VCDM; skalär kollaps; uppenbar horisont; numerisk relativitet;

    Sammanfattning : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. LÄS MER

  3. 2. Robust Aircraft Positioning using Signals of Opportunity with Direction of Arrival

    Master-uppsats, Linköpings universitet/Reglerteknik

    Författare :Erik Axelsson; Sebastian Fagerstedt; [2023]
    Nyckelord :Simultaneous localisation and mapping; direction of arrival; signals of opportunity; extended Kalman filter; positioning;

    Sammanfattning : This thesis considers the problem of using signals of opportunity (SOO) with known direction of arrival (DOA) for aircraft positioning. SOO is a collective name for a wide range of signals not intended for navigation but which can be intercepted by the radar warning system on an aircraft. LÄS MER

  4. 3. SECOND-ORDER DIVERGENCE-FREE FEM FOR MAGNETOHYDRODYNAMICS USING LAGRANGE POLYNOMIALS

    Kandidat-uppsats, Uppsala universitet/Institutionen för informationsteknologi

    Författare :Erik Björklund; Peter Mårtensson; Noah Waltman; [2023]
    Nyckelord :;

    Sammanfattning : AbstractMaxwell’s laws state that the divergence of a magnetic field always remains zero. In thecontinuous setting this is true for the magnetohydrodynamics equations. However, in thediscrete setting, the solution does not always remain divergence-free. LÄS MER

  5. 4. Utveckling och utvärdering av en funktionssäker pulsgivare : Konkretisering och vidareutveckling av en patenterad lösning vilken ämnas detektera låsta lager

    Master-uppsats, Mälardalens universitet/Akademin för innovation, design och teknik

    Författare :Kim Bojnell; [2023]
    Nyckelord :Pulsgivare; Mekanisk konstruktion; Driftsäkerhet; Funktionssäkerhet; Tillståndsövervakning; Feleffektanalys; Underhåll; Produktutveckling;

    Sammanfattning : An emerging industrial automation has led to higher demands required for construction of encoders to ensure functionality of automated processes. The main purpose of the encoder is to provide data which indicates the condition of a drive system. LÄS MER

  7. 5. Virtual Sensing for Cluster Vacuum Control

    Master-uppsats, KTH/Skolan för industriell teknik och management (ITM)

    Författare :Carl Egenäs; Axel Sacilotto; [2023]
    Nyckelord :;

    Sammanfattning : The purpose of this project was to develop a virtual sensing model in order to estimate the vacuum level in the milking cluster with data collected further along the milk tube. Measuring the cluster vacuum level is desirable for many applications, such as control and monitoring, but due to the cow's tendency to kick, chew and stomp on anything within reach, placing a sensor in or close to the cluster is both difficult and impractical. LÄS MER