Closed-loop wind tunnel with improved performance - has large number of fans and fresh-air vents

摘要

The wind tunnel has two proving tubes of different dimensions (3, 4) leading to a diffusor constructed from a group of 25 square tubes (7). The tubes are bent through an angle at the corner of the tunnel and contain gratings and fresh air ventilators controlled by flap valves at this point. A second diffusor (9) is placed between the two right-angle bends. At the beginning of the straight leg of the tunnel are 25 fan blowers (17) and aerofoils, each blower occupying one of the square-section tubes. The tubes terminate a short distance after the blowers (25), giving way to a large diffusor (26), corner elements (32, 34) and wide-angle diffusor (36). The air then passes through a conical chamber with rectifier and damping filter (42) before entering the measurement area.