The test section has a rectangular cross-section 8 feet high, 12 feet wide, and is 10 feet long with 1.5 feet high (45º) fillets in all four corners. The actual cross-sectional area is 91.5 square feet due to the fillets. See Figure 7 for a cutaway view.
The test section is on the second floor of the building, level with both the observation deck and the model deck. Models are installed by opening the test section ceiling. An overhead ½-ton hoist allows the models to be lifted from the ground floor and lowered into the test section through the test section ceiling. The motorized ceiling moves on tracks to create a 108" x 117" entrance to the test section. The test section can be viewed from the top through a 28½" x 40" window. Additional ceiling windows are available to view more of the model.
The test section floor is fabricated of removable 7/16" thick aluminum plates. The fore and aft center plates can be interchanged with viewing windows to allow for observing the underside of the model.
Schematic of the Test Section floor including dimensions
The port side of the test section is the observation deck. It provides a view of the model through a 44" x 87¼" window. The model deck also provides a view of the test section through two 28½" x 45" windows located in the two access doors. Opening both doors provides a 95" x 60" entrance to the test section.
The test section is vented to the atmosphere by two vents (5 feet long, 2 inches wide) located on the walls at the trailing edge of the test section. The vents keep the test section static pressure equal to approximately atmospheric pressure.
The upper-corner fillets have four 100-watt halogen lights on each side of the test section that can be turned on/off for obtaining the proper lighting conditions.
Test Section Cut Away View
Test Section Conditions
A detailed upflow and dynamic pressure calibration of the test section was conducted using a five-hole probe and a NACA 0015 wing to determine the flow qualities. The upflow angle is -0.012° for normal tests. Testing with calibration and commercial models have shown a negligible crossflow. A detailed survey of the test section using a hot-wire anemometer shows a nominal turbulence intensity of 0.72%. The average year-round temperature is 52.0°F with an average pressure of 2090.2 psf (readings taken from SeaTac International Airport).