{ "id": "0909.2557", "version": "v1", "published": "2009-09-14T14:31:52.000Z", "updated": "2009-09-14T14:31:52.000Z", "title": "Uniqueness and Instability of Subsonic--Sonic Potential Flow in A Convergent Approximate Nozzle", "authors": [ "Pan Liu", "Hairong Yuan" ], "comment": "9 pages", "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "We proved uniqueness and instability of the symmetric subsonic--sonic flow solution of the compressible potential flow equation in a surface with convergent areas of cross--sections. Such a surface may be regarded as an approximation of a two--dimensional convergent nozzle in aerodynamics. Mathematically these are uniqueness and nonexistence results of a nonlinear degenerate elliptic equation with Bernoulli type boundary conditions. The proof depends on maximum principles and a generalized Hopf boundary point lemma which was proved in the paper.", "revisions": [ { "version": "v1", "updated": "2009-09-14T14:31:52.000Z" } ], "analyses": { "subjects": [ "35J70", "35B50", "76H05" ], "keywords": [ "convergent approximate nozzle", "subsonic-sonic potential flow", "uniqueness", "instability", "symmetric subsonic-sonic flow solution" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0909.2557L" } } }