Challenging the large eddy simulation technique with advanced a posteriori tests

The large eddy simulation (LES) technique will soon be 50 years old. SinceDeardorff’s first papers in 1970 introducing this approach, major advances in thetheory of LES and its computational implementation have been made and widelyadopted. However, in terms of validation, LES studies continue to largely focus onthe first- and second-order statistics, which in fact are the same tests that Deardorffconducted 45 years ago. Further advances in LES and wider adoption for new flowsrequire advanced and more challenging tests to be developed and documented to serveas benchmarks. The paper by Stevens, Wilczek & Meneveau (J. Fluid Mech., 2014,vol. 757, pp. 888–907) does precisely that. The authors demonstrate the ability ofLES to capture the recently established log-law of streamwise velocity variance andthe related log-laws for even-order statistics up to order 10, as well as the departureof these statistics from a Gaussian distribution. The paper also provides key insightsinto the role of grid resolution on the computed turbulence field.