Turbulence

The response of a dynamical system to a simple shear deformation often reveals rich properties: near wall features, rheology of suspension, stability properties, etc. When homogeneous turbulence is sheared, properties similar to those appearing in more general inhomogeneous flows appear: off-diagonal Reynolds stresses, anisotropic scales, hairpin vortices. To investigate these properties without wall-specific effects, I developed an algorithm that solves the sheared Navier-Stokes equations in real space using shear-periodic boundary conditions to allow for unbounded shear.

Related publications:

• Kasbaoui, M. H., Kulkarni, T. & Bisetti, F. Direct numerical simulations of the swirling von K ́arm ́an flow using a semi-implicit moving immersed boundary method. Computers & Fluids 230, 105132 (2021).
• Kasbaoui, M. H., Koch, D. L. & Desjardins, O. The rapid distortion of two-way coupled particle- laden turbulence. Journal of Fluid Mechanics 877, 82–104 (2019).
• Kasbaoui, M. H. Turbulence modulation by settling inertial aerosols in Eulerian-Eulerian and Eulerian-Lagrangian simulations of homogeneously sheared turbulence. Phys. Rev. Fluids 4, 124308 (2019).
• Kasbaoui, M. H., Patel, R. G., Koch, D. L. & Desjardins, O. An algorithm for solving the Navier–Stokes equations with shear-periodic boundary conditions and its application to homo- geneously sheared turbulence. Journal of Fluid Mechanics 833, 687–716 (2017).