Periodic hill flow simulations with a parameterized cumulant lattice Boltzmann method

The article is concerned with the assessment of a cumulant lattice Boltzmann method in wall-bounded, separated turbulent shear flows. The approach is of interest for its resolution-spanning success in turbulent channel flows without using a specific turbulence treatment. The assessment focuses upon the flow over a periodic hill, which offers a rich basis of numerical and experimental data, for Reynolds numbers within 700 <= Re <= 37,000. The analysis involves the mean flow field, second moments and their invariants, as well as spectral data obtained for a wide range of resolutions with 2 less than or similar to Delta xi+less than or similar to 100. With the emphasis on a recently published parameterized cumulant collision operator, the universality of the value assigned to a stability preserving regularization parameter is assessed. Reported results guide resolution-dependent optimized values and indicate a required minimum resolution of Delta xi+approximate to 30. Analog to the findings for attached turbulent shear flows, the approach appears to adequately resolve complex turbulent flows without the need for ad hoc modeling for a range of scale resolving resolutions.

Automated summary

The article assesses a cumulant lattice Boltzmann method in wall-bounded, separated turbulent shear flows. The approach successfully resolves complex turbulent flows without the need for ad hoc modeling by using a recently published parameterized cumulant collision operator. The evaluation focuses on the flow over a periodic hill and determines the required minimum resolution.