Wind Tunnels were developed during the late 1800's when it was recognized that outside conditions were too uncertain to plan and execute the testing required to aid in man's quest to fly. As John Smeaton, in a paper read before the Royal Society in 1759, stated: "In trying experiments on wind mill sails the wind itself is too uncertain to answer the purpose; we must have recourse to an artificial wind."

What began as a basic tool for investigating aerodynamics has developed into a piece of equipment vital for developing and refining a wide range of a basic scientific knowledge and consumer products. Everything from aircraft, automobiles, computer chips, gas fireplaces, bicyclists, to the evaporation of common household cleaners can be tested in a wind tunnel.

The test section is the most important part of any wind tunnel, since it is the area where all of the work is performed. The remainder of the tunnel is, in essence, a set of, well designed, HVAC ducts guiding the airstream to this one critical area. The test section can be supplied with as much access as is required by the testing. The test section available with our standard designs incorporates a removable ceiling secured with quick release fasteners. If desired, the floor can also be made to be removable or the arrangement can be rotated 90°enabling one or both sidewalls to be removable. A limited number of ports (up to 15.2cm (6") in diameter is standard and up to 30.5cm (12") can be supplied) can be machined in any of the test section surfaces. Flanged Plexiglas plugs close the ports during operation.

Features that we have supplied in the past, but not considered standard, include: either diverging ceiling and floor panels or sidewalls to account for the boundary layer growth through the test section; hinged windows supported by gas springs for easy access to the model under test; recessed panels for customer test jigs; removable floor section(s) for inserting floor strut balances; two dimensional (either X-Y or Y-Z) or three dimensional traversing systems arranged for manual or stepper motor control; offset false surfaces for boundary layer work; and boundary layer suction on any combination of surfaces. Look into our instrumentation section to view many of the standard options offered.

Water Tunnel

For the majority of applications, air provides the most suitable testing medium. However, complex, three-dimensional flow fields are better understood through visualization. Smoke traces generated in wind tunnels tend to be hard to control and dissipate rapidly downstream of the injection point. Visualization of the individual flow streamlines is not something easily undertaken.

A liquid can be used as the visualization medium, with water being the most common choice. The water allows a wide variety of visualization techniques to be employed. These can range from something as simple as food coloring injected into the flow or a laser sheet using the particulate suspended in the water for the seeding medium.

Engineering Laboratory Design has been designing and manufacturing water tunnels since 1986. Standard model test section sizes range from 6" x 6" up through 24" x 24". Flow rates are controlled through the variation of the pump RPM . This feature allows excellent velocity control from speeds up to 3 fps (~1m/s) to practically zero. All of the water tunnels are unpressurized, which permits excellent access to the model through the test section open surface. Dye models and additional test section features can be added to any of the standard designs.

Shear layer tunnels, systems for studying aquatic wildlife, applications that require different mediums, can all be easily accommodated with slight modifications to the standard designs