Introduction to Partial Differential Equations Weijiu Liu Department of Mathematics University of Central Arkansas
Overview 11/9/2018
What are PDEs? An equation containing an unknown function and its partial derivatives: 11/9/2018
Three Big Classes of Equations Parabolic equations. Two simple example: Heat (diffusion) equation describing heat conduction: 11/9/2018
Convection-diffusion equation describing chemical diffusion and convection: Convection Diffusoin 11/9/2018
Hyperbolic equations: Wave equation describing the string vibration 11/9/2018
Elliptic equations: Laplace’s equation 11/9/2018
What we want to do about the equations Find an exact solution Find a numerical solution Study their well-posedness Study their stability Design a control law to force their solution to your desired one More … 11/9/2018
What are methods to find a solution Separation of variables Fourier series Fourier transformation Laplace transformation Method of characteristics Green functions D’Alembert’s formulas Symmetry analysis More … 11/9/2018
Tentative schedule Derivation of the heat equation, 1 week Separation of variables for solving the heat equation and Laplace’s equation, 2 weeks Fourier series, 3 weeks Derivation of the wave equation, 1 week Separation of variables for solving the wave equation, 1week High dimensional equations, 3 weeks Non-homogeneous problems, 2 weeks Equations on infinite domains, 1 week 11/9/2018
Equilibrium 11/9/2018
Dirichlet Boundary Conditions Steady equation 11/9/2018
Neumann Boundary Conditions Steady equation 11/9/2018