Contents XVII
12.3 The Spectral Collocation Method . . . . . . . . . . . . . . . . . . . . . . . . 550
12.4 The Galerkin Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552
12.4.1 Integral Formulation of Boundary Value Problems . . 552
12.4.2 A Quick Introduction to Distributions . . . . . . . . . . . . 554
12.4.3 Formulation and Properties of the Galerkin
Method .......................................555
12.4.4 Analysis of the Galerkin Method . . . . . . . . . . . . . . . . . 556
12.4.5 The Finite Element Method . . . . . . . . . . . . . . . . . . . . . 558
12.4.6 Implementation Issues . . . . . . . . . . . . . . . . . . . . . . . . . . 564
12.4.7 Spectral Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566
12.5 Advection-Diffusion Equations . . . . . . . . . . . . . . . . . . . . . . . . . . 568
12.5.1 Galerkin Finite Element Approximation . . . . . . . . . . . 569
12.5.2 The Relationship between Finite Elements and
Finite Differences; the Numerical Viscosity . . . . . . . . 572
12.5.3 Stabilized Finite Element Methods . . . . . . . . . . . . . . . 574
12.6 A Quick Glance at the Two-Dimensional Case . . . . . . . . . . . . 580
12.7 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583
12.7.1 Lubrication of a Slider . . . . . . . . . . . . . . . . . . . . . . . . . . 583
12.7.2 Vertical Distribution of Spore Concentration over
Wide Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 584
12.8 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586
13 Parabolic and Hyperbolic Initial Boundary Value
Problems .................................................589
13.1 The Heat Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589
13.2 Finite Difference Approximation of the Heat Equation . . . . . 591
13.3 Finite Element Approximation of the Heat Equation . . . . . . . 593
13.3.1 Stability Analysis of the θ-Method................595
13.4 Space-Time Finite Element Methods for the Heat
Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 601
13.5 Hyperbolic Equations: A Scalar Transport Problem . . . . . . . . 604
13.6 Systems of Linear Hyperbolic Equations . . . . . . . . . . . . . . . . . . 607
13.6.1 The Wave Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608
13.7 The Finite Difference Method for Hyperbolic Equations . . . . 609
13.7.1 Discretization of the Scalar Equation . . . . . . . . . . . . . 610
13.8 Analysis of Finite Difference Methods . . . . . . . . . . . . . . . . . . . . 611
13.8.1 Consistency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612
13.8.2 Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612
13.8.3 The CFL Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613
13.8.4 Von Neumann Stability Analysis . . . . . . . . . . . . . . . . . 615
13.9 Dissipation and Dispersion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 618
13.9.1 Equivalent Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . 619
13.10 Finite Element Approximation of Hyperbolic Equations . . . . 624
13.10.1 Space Discretization with Continuous and
DiscontinuousFinite Elements ...................625