Topological Fluid Mechanics (MAGIC052) |
GeneralDescription
The title Topological Fluid Mechanics covers a range of methods for understanding fluid mechanics (and related areas) in terms of the geometry and topology of continuous fields. For example in ideal fluid mechanics the vorticity field can be considered: by Kelvin's theorem the field is frozen, moving in the fluid flow and its topology is conserved. Topological invariants can thus be used to describe aspects of the fluid flow. There are similar applications in magnetohydrodynamics, relevant to the Solar magnetic field.
This course will be lectured by Andrew Gilbert and Mitchell Berger (University of Exeter) SemesterSpring 2012 (Monday, January 16 to Friday, March 23) Timetable
PrerequisitesPREREQUISITES:
knowledge of vector calculus and fluid mechanics up to 3rd year undergraduate level. basic knowledge of pure mathematics, in particular group theory up to 2nd year undergraduate level. NOT REQUIRED: knowledge of magnetohydrodynamics: this will be developed where needed. knowledge of pure mathematics beyond basic group theory. NOTE: ideas will be developed in concert with, and motivated by, applications and strongly based on examples. The course will have an applied mathematics feel to it, rather than a very formal development. SyllabusOutline Syllabus
This course will be lectured by Andrew Gilbert (AG) and Mitchell Berger (MB) of the University of Exeter. Part I (AG): basics, helicity and relaxation (3 lectures) Background and motivation, hydrodynamics and magnetohydrodynamics. Revision of Kelvins theorem and magnetic analogies. Fluid, magnetic and cross helicity, geometrical interpretation. Magnetic relaxation. Part II (MB): knots, tangles, braids and applications (4 lectures) Link, twist and writhe of flux and vortex tubes. Braiding of flux and vortex tubes. Vortex tangles in quantum fluids and vortex tubes in turbulence, crossing numbers. Chaotic mixing, stirrer protocols, pA maps and topological entropy. Part III (AG): dynamics of vortex filaments and singularities (2 lectures) Vortex tube dynamics, local induction approximation, invariants, solitons. The singularity problem and approaches. Lecturer
Students
BibliographyNo bibliography has been specified for this course. AssessmentNo assessment information is available yet.
Problem set 1: vorticity, magnetic fields and helicity
Problem set 2: Vortex dynamics (part III of the course)
Problem Set 3: Topology, Helicity and Braids
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