Low Speed Aerodynamics Lab

A wind tunnel is a machine which can simulate the movement of air around an aircraft in flight. In the wind tunnel, the aeronautical engineer can control the conditions that effect the forces and motion of the aircraft. By making careful measurements of the forces on a model of the aircraft. the engineer can determine the magnitude of the forces on the real, full-size aircraft. The wind tunnel model can also be used for diagnostics to make a detailed determination of how the air moves around or through the aircraft

Aerodynamicists use wind tunnels to test models of proposed aircraft. In the tunnel, the engineer can carefully control the flow conditions which affect forces on the aircraft. By making careful measurements of the forces on the model, the engineer can predict the forces on the full scale aircraft. And by using special diagnostic techniques, the engineer can better understand and improve the performance of the aircraft.

Wind tunnels are designed for a specific purpose and speed range and there is a wide variety of wind tunnel types and model instrumentation. The model to be tested in the wind tunnel is placed in the test section of the tunnel. The speed in the test section is determined by the design of the tunnel. The choice of speed range affects the design of the wind tunnel due to compressibility effects.

For subsonic flows, the air density remains nearly constant and decreasing the cross-sectional area causes the flow to increase velocity and decrease pressure. Similarly, increasing the area causes the velocity to decrease and the pressure to increase. We want the highest possible velocity in the test section. For a subsonic wind tunnel, the test section is placed at the end of the contraction section and upstream of the diffuser. From a knowledge of the conservation of mass for subsonic flows, we can design the test section to produce a desired velocity or Mach number since the velocity is a function of the cross-sectional area. On the figure, we note the changes in Mach number, velocity and pressure through a subsonic wind tunnel design. The plenum is the settling chamber on a closed return tunnel, or the open room of an open return design.





Department of Aeronautical Engineering of ACE has the LARGEST WIND TUNNEL among the Educational Institutions in Kerala.


  • Test Section 600mm x 600mm x 2000mm
  • flow speed 50 m/s
  • External 6-component balance
  • Commissioned 2015
  • Purpose:
    • Testing of aircraft, ship and automotive vehicle models,
    • Determination of wind loads on structures,
    • Calibration of wind and other flow measurement instruments