INVARIANCE PRINCIPLES AND APPROXIMATION IN TURBULENCE DYNAMICS.
KRAICHNAN (ROBERT H) PETERBOROUGH N H
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Known expansion schemes for turbulence statistical functions appear to diverge at high Reynolds numbers. The expansions are an illusory guide for choosing a closure approximation for the statistical equations. They do not provide a means either of constructing successively more accurate approximations or of estimating the error in any given approximation. In this situation, an important principle for constructing appropriate approximations is to retain as much as possible of the basic conservation, invariance, and boundedness properties of the exact flow dynamics. Approximations which preserve such properties give a hope of qualitative agreement with reality. Unless some kind of convergent and practicable kind of approximation scheme is developed, any accurate quantitative prediction from turbulence theory must be regarded as an accident or miracle. Author
- Theoretical Mathematics
- Fluid Mechanics