New features in turbulence dissipation

Abstract

An iconic phenomenon in turbulence is the complex energy transfer cascading across a wide range of scales. Despite large-scale motions, universal behaviors occur when isotropic condition is restored at Kolmogorov's scales. However, such mechanical equilibrium can be disrupted by external forces like shears and shock waves. A pervasive and long-lasting discussion is the dynamic processes involved in driving the systems toward local isotropy. We present a theoretical analysis that unveils the dissipative mechanism, which contributes to isotropic conditions. Surprisingly, the mechanism depends on the transport of vorticity and strain. The high-resolution shock-resolving data of shock-turbulence interactions support the findings of this new feature in dissipation. The physical characters of this dissipative mechanism and their contributions to isotropy and overall dissipation are discussed. Despite the dissipative connection, the new mechanism is not sign definite and is associated with other functions.