RANS Model-based Constant Temperature Anemometry Examination to Validate Negligible Wind Tunnel Blockage Effect on Developed Multi-scale Generated Grid Turbulence

The aim of this study is to quantitatively assess the effect of wind tunnel blockage on multi-scale generated turbulence and to analyze the results in comparison with the results of previous studies. In particular, the study focuses on the mainstream weak acceleration phenomena and their turbulence characteristics, and the effects are evaluated using acceleration parameters. The decay exponent calculated by introducing a turbulence time scale was larger than the results in the previous study for square lattice turbulence, indicating a rapidly decaying field. An evaluation of the dependence on flow velocity was also carried out, and the results obtained by varying the set flow velocity confirm that the effect of acceleration on turbulent energy, dissipation rate, length scale and time scale is independent of flow velocity. Compared to the measurement uncertainty, the effect of acceleration was small and no statistically significant differences were found. The results of this study provide important information for the quantitative assessment of the impact of weak acceleration phenomena in the main flow due to blockage effects in the wind tunnel test section on multi-scale generated turbulence.