Computational PDEs I (Theorie und Numerik partieller Differentialgleichungen I)

Summer Semester 2024


Lecturer: Christos Pervolianakis
Office: Ernst-Abbe-Platz 2, Room 3533
Email: christos.pervolianakis (AT) uni-jena.de
Dates: Monday 12-14Uhr and Thursday 08-10Uhr, Ernst-Abbe-Platz 2 - R 3517.
Office hours: Thursday 10-13Uhr.


Description

The solutions of partial differential equations cannot usually be specified by closed formulas, so we need to numerically approximate them. The lecture deals with linear equations of both elliptic and parabolic type. The analytical solution theory (existence and interpretation) which is developed for these and the finite element method for the numerical approximation will be the main objectives of the lecture.


Recommended knowledge

Course evaluation


Lecture notes: .pdf

via Moodle with uni-account


Programming Exercises

Here you will find the some numerical exercises that are not mandatory, but interesting.

Programming Projects


Announcements

02.04.2024  The course lecture starts on 04.04.2024. We will solve the theoretical exercises every second Thursday e.g., 11.04, 25.04, 23.05, 06.06, 20.06, 04.07.

02.04.2024  As soon as we finish a section, I will add this section to the lecture notes.

15.04.2024  The lectures on 10.06 and 13.06 are cancelled. Their replacement will be on 14.05 and 18.06 in 14:00-16:00 Uhr at HS 5 Abbeanum, Fröbelstieg 1.


Lecture Calendar

04-04-2024  Review of basic results from mathematical analysis (Hilbert spaces, weak derivative, Sobolev spaces, approximation by smooth functions for \(H^1\) functions).

08-04-2024  Trace estimates within a triangle \(K\subset\mathbb{R}^2\) and on \(\Omega\subset\mathbb{R}^2\), where \(\Omega\) a polygonal Lipschitz domain. Riesz Represetantion Theorem (without proof). Lax-Milgram Lemma (without proof).

11-04-2024  Exercises 1-5.

15-04-2024  Proof of Lax-Milgram Lemma. Definition of classical and weak solution of Poisson equation with homogeneous boundary conditions. Proof of the existence and uniqueness of weak solution \(u\in H^1_0(\Omega)\) using Lax-Migram Lemma.

18-04-2024  Dirichlet Principle. Weak form of Poisson equation with non-homogeneous Dirichlet and Neumann conditions. Approximation problem, existence and uniqueness. Error in energy norm.

22-04-2024  Error in energy norm, Cea's Lemma and Aubin-Nitsche Lemma (Proofs). Error in \(H^1\) and \(L_2\) for the Poisson equation with zero boundary conditions where the finite dimensional space \(V_h\) satisfies an approximation property.

25-04-2024  Exercises 6-9.

29-04-2024  Finite element spaces. Construction of finite element spaces. Triangular elements (linear, quadratic Lagrange and cubic Hermite element).

02-05-2024  Rectangular elements (Bilinear, Biquadratic Lagrange Finite Element). Continuous piecewise linear interpolation.

06-05-2024  Piecewise linear, continuous functions on a triangulation. Shape regularity. A local estimate for the interpolant.

13-05-2024  Scaling estimates between functions on reference and generic domain. Proof a local estimate for the interpolant using Bramble-Hilbert lemma in \(L^2\) norm and \(H^1\) seminorm.

14-05-2024  Bramble-Hilbert lemma (Proof). Inverse inequality on quasi-uniform triangulations. Non-conforming finite elements (Motivation).

16-05-2024  Petrov-Galerkin method. Generalized Lax-Milgram Lemma.

23-05-2024  Exercises 10,15,16.

27-05-2024  Error estimates for Petrov-Galerikin method. Introduction to Generalized Galerkin method and its existence and uniqueness.

30-05-2024  First and second Strang Lemma. Application of the Strang lemma (Effects of numerical integration).

03-06-2024  Application of the Strang lemma (Effects of numerical integration). Crouzeix Raviart Element.

06-06-2024  Crouzeix Raviart Element. Error estimation

17-06-2024  Introduction to time dependent problems(Heat equation). Bochner spaces and definition of the weak solution. Construction of the solution via Galerkin method.

18-06-2024  Energy estimates. Existence and uniqueness of the weak solution. For higher regurarity see Chapter 7.1, Reference 8.

20-06-2024  Galerkin method for Heat Equation. Elliptic(Ritz) Projection, \(R_h\,:\,H^1 \to V_h^r,\,r\geq 1,\) integer. Definition and error estimates in \(L^2\) norm and \(H^1\) seminorm.

24-06-2024  Error estimates for the semi-discrete scheme in \(L^2\) norm and \(H^1\) seminorm.

27-06-2024  Fully-discrete scheme with implicit Euler. Matrix formulation and error estimates in \(L^2\) norm.

01-07-2024  Fully-discrete scheme with Crank-Nicolson and explicit Euler. Matrix formulation and error estimates in \(L^2\) norm.


Literature



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