Summary Report No. 60


The Need for De-Aliasing in a Chebyshev Pseudo-Spectral Method

M. Uhlmann (June 2000)


In the present report, we attempt to estimate whether the computational overhead due to the explicit removal of Chebyshev-pseudo-spectral-induced aliasing errors is necessary in a DNS of plane channel flow. We first recall the origin of aliasing errors in a Chebyshev method before turning to results from different test cases: analytical; transition to turbulence; fully-developed turbulence.

Our results indicate that corrective action can slightly improve the quality of the solution in situations where the resolution is marginal. We do not find conclusive evidence that supports the use of the de-aliasing strategy under non-marginal conditions.


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