Dissipation scaling for adjacent turbulent streams

Establish the dissipation scaling for two adjacent turbulent streams of comparable intensity when only small-scale intermittency exists in the outer region of a wind-turbine wake.

Background

The study finds that low- and moderate-intensity free-stream turbulence produces a clear non-equilibrium dissipation scaling in the outer wake, with the normalised dissipation coefficient satisfying approximately $C_{\varepsilon}\sim\sqrt{Re_D}/Re_{\lambda}$. For the most intense free-stream turbulence, however, the wake-generated and ambient turbulence become comparable in intensity, large-scale intermittency is suppressed, and no comparable scaling can be identified using a single turbulent Reynolds number.

The unresolved problem is to determine an appropriate dissipation-scaling framework for two adjacent turbulent streams of comparable intensity, particularly in the regime where intermittency is confined to small scales in the outer wake.