Active Turbulence Generation in a Laboratory Wind Tunnel

Abstract

A new type of active turbulence generator was designed. It can induce strong, homogeneous, and quasi-isotropic turbulence with a high turbulence Reynolds number in a laboratory wind tunnel. The resultant turbulence had intensity of more than 30{%} and an integral scale exceeding 200 mm just downstream of the generator. The maximum turbulence Reynolds number reached Re$λ$≈ 600, which is about one order of magnitude larger than that of the grid turbulence with the same mesh Reynolds number, ReM. The energy spectrum of the strong turbulence had a clear inertial subrange spreading for more than two orders of magnitude in wave-number. The features of the spectrum are favorably comparable with those for the grid turbulence of ReM≈ 106