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Constraints on possible singularities for the unsteady transonic small disturbance (UTSD) equations

✍ Scribed by Irene M. Gamba; Rodolfo R. Rosales; Esteban G. Tabak


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
332 KB
Volume
52
Category
Article
ISSN
0010-3640

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✦ Synopsis


We discuss the singular behavior of solutions to two-dimensional, general secondorder, uniformly elliptic equations in divergence form, with bounded measurable coefficients and discontinuous Dirichlet data along a portion of a Lipschitz boundary. We show that the conjugate to the solution develops a singularity that is at least logarithmic along the boundary at the points of discontinuity in the boundary data.

A problem like this arises in the study of self-similar solutions to the hyperbolic conservation laws in two space dimensions given by the unsteady transonic small disturbance (UTSD) flow equations. These solutions model the reflection of a weak shock wave upon a thin wedge in the regime where the von Neumann paradox applies.

The present result provides a step in the direction of understanding the nature of the solutions to the UTSD equations near a triple point. It shows that the flow behind the triple point cannot be strictly subsonic under some mild assumptions on the solutions.