Turbulence Generated in Active Grid Mode Using a Multi-Fan Wind Tunnel

Abstract

The wind tunnel used is equipped with an array of small fans (9 columns×11 rows), each of which is independently controlled via a personal computer. To establish an efficient driving mode for generating high-Reynolds number isotropic turbulence, a new driving mode (“active grid mode”) is attempted where the active and inactive fans are grid-like arranged. The characteristics of turbulence are investigated for two kinds of external fluctuated signals. The flow structure of the turbulence generated by the active grid mode is proposed.