Mahendra Verma (Physics Department, Indian Institute of Technology, Kanpur, India) - Is there a universal theory of turbulence?

Turbulence is an open physics problem. I will try to highlight many facets of the turbulence problem. In 1941, Kolmogorov enunciated a universal theory of fluid turbulence according to which the energy spectrum of homogeneous and isotropic flows exhibit k^{-5/3} energy spectrum.  Though many experiments and simulations verify the above law, the theory is not applicable in the presence of additional forces or walls.  The buoyancy-driven stably-stratified flows show k^{-11/5} spectrum, but thermally-driven turbulence exhibits Kolmgorov-like properties.  Rotating and magnetohydrodynamic turbulence exhibit properties different from Kolmogorov theory.

Thus, there is no universal theory of turbulence, at least at present. In this talk, I will attempt to describe the varied phenomena in the framework of variable energy flux.

Reference: M. K. Verma, Variable Energy Flux in Turbulence (Topical Review), J. Phys. A, 55, 013002 (2022)