Treatment of the Discontinuity in the Spin-up Problem with Impulsive Start.

Abstract

The spin-up equation derived from the Wedemeyer model is considered. For an impulsive start, the boundary conditions prescribe a discontinuity in the velocity on the boundary. The finite difference solution of the spin-up equation is significantly in error unless the discontinuity is treated properly. A solution in the neighborhood of the discontinuity is derived by a direct coordinate expansion, after a stretching transformation is applied. This solution is used as an approximate initial condition; the approximation is evaluated and tests show that the error is negligible. The details are given for laminar Ekman layers; just the results are given for the turbulent case.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1983
Accession Number
ADA133682

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  • Nathan Gerber
  • Raymond Sedney

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  • Ballistic Research Laboratory

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