RECIRCULATING VERTICAL WIND TUNNEL

Disclosed in this patent application is a turning vane structure for a corner of a vertical wind tunnel, the vertical wind tunnel forming a recirculating airflow plenum, the turning vane structure comprising:a frame structure at least partially positioned outside the recirculating airflow plenum;the frame structure includes two arches;the arches span between ends of a centerline;each arch is inclined at an angle relative to the horizontal plane;the arches extend in opposite directions from one another; and turning vanes mounted along each of the two arches, the turning vanes positioned inside the recirculating airflow plenum and configured to redirect airflow through the corner.