Sökning: "teknisk analys"

Visar resultat 16 - 20 av 164 avhandlingar innehållade orden teknisk analys.

1. 16. Boundary singularities of plurisubharmonic functions

   Författare :Mårten Nilsson; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pluripotential theory; envelope of plurisubharmonic functions; complex Monge-Ampère equation; Jensen measures;

   Sammanfattning : We study the Perron–Bremermann envelope P(μ, φ):=sup{u(z) ; u ∈ PSH(Ω), (ddcu)n≥ μ, u^* ≤ φ} on a B-regular domain Ω. Such envelopes occupy a central position within pluripotential theory as they, for suitable μ and φ harmonic and continuous on the closure of Ω, constitute unique solutions to the Dirichlet problem for the complex Monge–Ampère operator. LÄS MER

3. 17. Hybrid Methods for Unsteady Fluid Flow Problems in Complex Geometries

   Författare :Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hybrid methods; finite difference methods; finite volume methods; coupling procedure; stability; efficiency; artificial dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Beräkningsvetenskap med inriktning mot numerisk analys;

   Sammanfattning : In this thesis, stable and efficient hybrid methods which combine high order finite difference methods and unstructured finite volume methods for time-dependent initial boundary value problems have been developed. The hybrid methods make it possible to combine the efficiency of the finite difference method and the flexibility of the finite volume method. LÄS MER

4. 18. Analysis and numerical methods for multiscale problems in magnetization dynamics

   Författare :Lena Leitenmaier; Olof Runborg; Carlos Garcia-Cervera; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Sammanfattning : This thesis investigates a multiscale version of the Landau-Lifshitz equation and how to solve it using the framework of Heterogeneous Multiscale Methods (HMM). The Landau-Lifshitz equation is the governing equation in micromagnetics, modeling magnetization dynamics. LÄS MER

5. 19. Uncertainty quantification for time varying quantities in turbulent flows

   Författare :Donnatella Xavier; Philipp Schlatter; Saleh Rezaeiravesh; Ricardo Vinuesa; David Moxey; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; uncertainty; variance estimator; autoregressive models; turbulence; computational fluid dynamics; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : Quantification of uncertainty in results is crucial in both experiments and simulations of turbulence, yet this practice is notably underutilized. This thesis project delves into statistical tools within the framework of uncertainty quantification to systematically quantify uncertainties that occur in the time varying quantities of turbulence. LÄS MER

7. 20. Adjoint-based aerodynamic shape optimization

   Författare :Olivier Amoignon; Martin Berggren; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Sammanfattning : An adjoint system of the Euler equations of gas dynamics is derived in order to solve aerodynamic shape optimization problems with gradient-based methods. The derivation is based on the fully discrete flow model and involves differentiation and transposition of the system of equations obtained by an unstructured and node-centered finite-volume discretization. LÄS MER