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On hypersonic self‐induced separation, hydraulic jumps and boundary layers with algebraic growth
Author(s) -
Gajjar J.,
Smith F. T.
Publication year - 1983
Publication title -
mathematika
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 29
eISSN - 2041-7942
pISSN - 0025-5793
DOI - 10.1112/s0025579300010433
Subject(s) - froude number , hydraulic jump , mathematics , adverse pressure gradient , reynolds number , boundary layer , mechanics , algebraic number , pressure gradient , flow (mathematics) , boundary (topology) , supercritical flow , hypersonic speed , geometry , flow separation , mathematical analysis , physics , turbulence
Summary Analytical and numerical properties are described for the free interaction and separation arising when the induced pressure and local displacement are equal, in reduced terms, for large Reynolds number flow. The interaction, known to apply to hypersonic flow, is shown to have possible relevance also to the origins of supercritical (Froude number > 1) hydraulic jumps in liquid layers flowing along horizontal walls. The main theoretical task is to obtain the ultimate behaviour far beyond the separation. An unusual structure is found to emerge there, involving a backward–moving wall layer with algebraically growing velocity at its outer edge, detached shear layer moving forward and, in between, reversed inertial flow uninfluenced directly by the adverse pressure gradient. As a result the pressure then increases like (distance) m , with m = 2(√(7)–2)/3 (= 0.43050 …), and does not approach a plateau. Some more general properties of (Falkner–Skan) boundary layers with algebraic growth are also described.