Ankara Wind Tunnel (AWT) is a closed return, horizontal axis, atmospheric wind tunnel operating at low subsonic speeds and has a closed test section. Tunnel test section sizes are 3.05 m width, 2.44 m height and 6.10 m length. The tunnel circuit is reinforced concrete and test section is wooden. More than 80 m/s (288 km/h) air speed can be reached in the empty test section. The axial turbulence level of the tunnel is 0.15% and the total turbulence level is 0.62%. Many types of experiments can be carried out in wind tunnels such as investigating the aerodynamic behavior of aircraft, helicopters, UAVs, parachutes, automobiles, trucks, buses and motorcycles, determining the interaction of objects such as sirens and lightning rods with air and examining their strength in storm environment. The construction of tunnel was decided in 1941. Tunnel construction was started by Ministry of Education in 1946, motor and propeller were installed in 1949 and tunnel was partially operational in 1950. AWT remained idle until 1993 and operational responsibility was given to TUBITAK SAGE. In the same year, propeller, motor and electrical equipment were reviewed to start the tunnel again and the tunnel was fully operational in 1996. Tunnel maintenance, repair and capability enhancement activities are regularly carried out by TUBITAK SAGE since 1993. In 2000 AWT has become a member of the Subsonic Aerodynamic Testing Association (SATA). SATA is the leading worldwide organization established to discuss ideas such as the design, operation, maintenance, physical measurement and instrumentation of low speed wind tunnels.
The full or scaled model to be tested in AWT is mounted in the test section and the desired air speed is sustained. The model is set to desired angles using the model support system (MSS). Aerodynamic forces acting on the model are measured using external or internal balances. Flow visualization tests can be performed with various techniques to investigate the flow on the model. AWT has been actively used by universities, civil sector and defense industry companies such as TUBITAK SAGE, TAI, ROKETSAN and ASELSAN.
Capabilities
- Load Measurement Tests
◦ External Balance System
◦ Internal Balance System (22 mm, 35 mm and 44 mm diameter)
◦ Model Support System, which is integrated to the external balance system and works with sting type internal balances
- Structural Strength Tests
- Flow Measurement Tests
◦ Surface Pressure Measurement with 64 channel pressure scanner
◦ Constant Temperature Hotwire Anemometry (CTA)
- Flow Visualization Tests
◦ Pressure Sensitive Paint
◦ Tuft, Smoke and Oil Flow Visualization Tests
It is possible to measure aerodynamic force and moment data precisely in the angle of attack range of -20˚ and 50˚ and sideslip angle range of -30˚ and 30˚ using model support system with a high positioning accuracy of 0.025˚. AWT is the only wind tunnel having pressure-sensitive paint system in Turkey. Since PSP method is a non-invasive method, measuring the pressure values becomes possible without causing any disturbance in the flow. Additionally, test section turbulence can be precisely measured using three-axis hot wire probe in CTA system.