Open Circuit Wind Tunnels

Fitting your exact requirements - low ceilings, limited access, obstacles and more


Because each AEROLAB open circuit wind tunnel is individually designed, one can be made to meet your exact requirements.

Open circuit wind tunnels do not directly re-circulate air. Rather, air is drawn in from the laboratory environment, passes through the test section and is returned back to the lab through the tunnel exhaust.

AEROLAB has made open circuit wind tunnels for many past customers who had special needs, such as low ceilings, limited access (small doorways) and obstacles such as building columns and overhead ducting.

AEROLAB offers cost effective tunnels in a variety of standard sizes:

  • 6×6 inch
  • 12×12 inch
  • 18×18 inch
  • 24×24 inch
  • 30×30 inch

AEROLAB also specializes in producing custom wind tunnels; with experience producing tunnels with test section sizes in excess of 40×40 inches, AEROLAB is prepared for your design requirements.  Start a conversation with one of our engineers for more information and to obtain a quotation, be sure to include any requirements (size, speed, shape).

Performance Specifications

  • Airspeed Range – customer-defined
  • Turbulence Level – typically less than 0.25% (depending upon laboratory conditions)


The contraction is the bell-shaped inlet. Aerodynamicist use the term “contraction ratio” to refer to the inlet-to-outlet area ratio. Although any contraction ratio is possible, 9:1 is a good compromise between physical size and test section turbulence levels.

AEROLAB uses either a fifth or a ninth-order polynomial to define a smooth transition between the tunnel inlet and the test section entrance.

Honeycomb Flow Straightener

To straighten incoming airflow, a “honeycomb” of long narrow tubes is employed. Every AEROLAB wind tunnel is supplied with a high quality, aluminum, high-aspect-ratio honeycomb flow straightener.

Turbulence-reducing Screens

All AEROLAB tunnels are supplied with two stainless steel turbulence-reducing screens. Also, sufficient space is provided within the wind tunnel framework to fit an additional two screens at a later date should the customer need extremely smooth flow for sensitive experiments.


See the Open Circuit Wind Tunnels Brochure.


Low Speed