This is the first book devoted to the least-squares finite element method (LSFEM), which is a simple, efficient and robust technique for the numerical solution of partial differential equations. The book demonstrates that the LSFEM can solve a broad range of problems in fluid dynamics and electromagnetics with only one mathematical/computational formulation. The book shows that commonly adopted special treatments in computational fluid dynamics and computational electromagnetics, such as upwinding, numerical dissipation, staggered grid, non-equal-order elements, operator splitting and preconditioning, edge elements, vector potential, and so on, are unnecessary.
This book introduces the basic theory of the least-squares method for first-order PDE systems, particularly the div-curl system and the div-curl-grad system. It is applied to the study of permissible boundary conditions for the incompressible Navier--Stokes equations, to show that the divergence equations in the Maxwell equations are not redundant, and to derive equivalent second-order versions of the Navier--Stokes equations and the Maxwell equations. This book covers diverse applications such as incompressible viscous flows, rotational inviscid flows, low- or high-Mach-number compressible flows, two-fluid flows, convective flows, and scattering waves.

Klappentext

This is the first monograph on the subject, providing a comprehensive introduction to the LSFEM method for numerical solution of PDEs. LSFEM is simple, efficient and robust, and can solve a wide range of problems in fluid dynamics and electromagnetics.

Inhalt

I. Basic Concepts of the LSFEM.- 1. Introduction.- 2. First-Order Scalar Equation in One Dimension.- 3. First-Order System in One Dimension.- II. Fundamentals of LSFEM.- 4. Basis of LSFEM.- 5. The Div--Curl System.- 6. The Div--Curl--Grad System.- III. The LSFEM in Fluid Dynamics.- 7. Inviscid Irrotational Flows.- 8. Incompressible Viscous Flows.- 9. Convective Transport.- 10. Incompressible Inviscid Rotational Flow. 11. Low-Speed Compressible Viscous Flows.- 12. Two-Fluid Flows.- 13. High-Speed Compressible Flows.- IV. The LSFEM in Electromagnetics.- 14. Electromagnetics.- V. Solution of Discrete Equations.- 15. The Element-by-Element Conjugate Gradient Method.- Appendices: A. Operations on Vectors.- B. Green's Formula.- C. Poincaré Inequality.- D. The Lax--Milgram Theory.- References.- Index.