Abstract
<p> <p id="x-x-x-x-"> If the Navier–Stokes equations are averaged with a local, spacial convolution type filter,ϕ¯¯¯=gδ∗ϕ, the resulting system is not closed due to the filtered nonlinear termuu¯¯¯¯. An approximate deconvolution operator DD is a bounded linear operator which satisfies </p> <p> u=D(u¯¯)+O(δα), <a title="Turn MathJax on"> Turn MathJaxon </a> </p> <p> where δδ is the filter width and α⩾2α⩾2. Using a deconvolution operator as an approximate filter inverse, yields the closure </p> <p> uu¯¯¯¯=D(u¯¯)D(u¯¯)¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯+O(δα). <a title="Turn MathJax on"> Turn MathJaxon </a> <p id="x-x-x-x-"> The residual stress of this model (and related models) depends directly on the deconvolution error,u−D(u¯¯). This report derives deconvolution operators yielding an effective turbulence model, which minimize the deconvolution error for velocity fields with finite kinetic energy. We also give a convergence theory of deconvolution as δ→0δ→0, an ergodic theorem as the deconvolution order N→∞N→∞, and estimate the increase in accuracy obtained by parameter optimization. The report concludes with numerical illustrations. </p> </p></p>
Original language | American English |
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Journal | Applied Mathematics and Computation |
Volume | 208 |
DOIs | |
State | Published - Feb 1 2009 |
Keywords
- Deconvolution
- LES
- Turbulence model
Disciplines
- Mathematics