2-Dimensional Model Mounting
2D-wall inserts can be mounted in the tunnel test section to obtain two-dimensional flow for testing
models. The model still uses the main KWT external balance. The walls extend from the floor to the
ceiling of the test section with a span of 41.5-inches between them. Dynamic pressure is measured using
four manifolded total ports and four manifolded static ports located 46.5 inches ahead of the test section
centerline. A detailed upflow angle and dynamic pressure calibration of the 2D test section, using a fivehole
probe, shows the upflow is -0.333°. End plate drag effects can be determined during the test by
using the 20” wake rake to measure the wake deficit, from which a drag effects can be calculated.
Top and Side View of 2D Inserts
A static pressure gradient of -0.0050 CP/ft exists in the 2D test section that is not present in the 3D
section. The gradient is present because the 2D inserts prevent the test section from being directly vented
to the atmosphere, combined with the increase in boundary layer thickness on the 2D walls. The static
pressure gradient is accounted for in data reduction by applying a buoyancy correction to drag.
2D Test Section (Top View)