Air enters the test section through a carefully designed contraction followed by an aluminum honeycomb flow straightener designed to ensure that the flow is steady in both magnitude and direction and has a flat transverse velocity profile. The Sub Sonic Open Circuit Wind Tunnel is simple and safe in operation. It is supplied as a complete self-contained facility mounted on castors for ease of movement. Main equipment comprises the tunnel with a three-component balance system (lift, drag and pitching moment) and an air speed indicator. One number of floor mount 3 component balance for lift force, drag force and pitching moment measurement is installed in the test section. A low angle diffuser at the outlet end contributes to flow stability in the test section. An axial flow fan is located at the outlet of the diffuser section.
Forces and moment data are digitally shown on LCD graphic display screen and are able to transfer to computer.
Adjustment of pitch angle of models can be made with the tunnel in operation.
Lift force: 0 to 100 N, sensitivity ±0.01 N
24 bit analogue to digital conversion of 3 strain gauge load cells for greater accuracy at low forces.
The accuracy of the tunnel and its instrumentation make it suitable for undergraduate and simple research work.
Drag Force: 0 to 50 N, sensitivity ±0.01 N
Pitching Moment: 0 to 2.4 Nm, sensitivity ±0.001 Nm.
