Computational Investigation of the Developing Jet from an Open Test Section Wind Tunnel*

Open test section wind tunnels offer distinct advantages in the study of unsteady gusts which travel at convective speeds in contrast to closed test sections where the disturbances travel at the speed of sound. Matching such configurations in computational studies bring additional challenges in terms of domain, boundary conditions, and the scales that must be resolved. This study focuses on the validation of a high-fidelity simulation of an open test section low-speed unsteady wind tunnel facility and analysis of the resulting flow physics. Results from a Delayed Detached Eddy Simulation matching the entire wind tunnel facility are compared to experimental measurements at steady and unsteady conditions. After validating the computational setup, further analysis of the behaviors of the pressure and velocity fields in the wind tunnel setup are investigated which are impractical to measure experimentally. The simulation results allow for a more complete understanding of the overall setup, including coupling of velocity fluctuations in the jet core to structures in the shear layers and the effects of global pressure fluctuations on the core during unsteady operation of the wind tunnel.