This requirement is for a closed-circuit wind tunnel with a 24-inch square test section capable of operating up to ~50 m/s and as low as 0.15 m/s using removable nozzle restriction plates, with turbulence intensity below 1%. The test section must accommodate various instrument ports, include a replaceable 15-inch test area, optical-quality glass sidewalls, and fit within a 32x8x7.5 ft footprint. The tunnel must use a vibration-isolated centrifugal fan with a variable-frequency drive controllable via LabVIEW (no wireless). Designs must include quantitative analysis (e.g., CFD) proving performance. Delivery is to Redstone Arsenal, AL.