Abstract

Discrete approximation of a flow field using anisotropic meshes causes “unphysical” anisotropy of the resolved part of the Reynolds stress tensor and of the subgrid scale stress tensor if common anisotropy measures such asūı̄ūj/q2− 1/3δijare used in order to characterize the turbulence structure. By evaluating model spectrum tensors the effect is investigated for isotropic and anisotropic turbulence. The deviation from a physical meaningful anisotropy state depends on various parameters such as the energy spectrum shape near the cutoff in wavespace, the cell aspect ratios, and the range of scales which are resolved. Subgrid kinetic energy must be distributed unequally among the normal stresses on an anisotropic mesh. For example, for aspect ratios Δx:Δy:Δz= 1:8:4, rms fluctuations of subgrid motions are shown to deviate by 9% in isotropic turbulence in the inertial subrange.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.