**9. Conclusion**

A general purpose return circuit low speed wind tunnel has been designed for the Aerody‐ namics Laboratory of the University of New South Wales. A contraction ratio of 7:1 and four turbulence reduction screens are used. Low turbulence level is achieved with the assistance of some innovative design features. The fan is located upstream of the first corner. Corner cascade and screen configurations have received special attention.

Other unusual aspects of the design are three sizes of interchangeable test sections in the speed ranges of 0-25 ft/sec, 0-100 ft/sec and 0 -200 ft /sec.

The fan is driven by a hydraulic motor which considerably simplifies power transmission and control problems in this application.
