AFRL Researchers Complete Blended Wing Body Wind Tunnel Tests Published Sept. 25, 2007 By Air Vehicles Directorate AFRL/VA WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- AFRL researchers completed tests of a blended wing body (BWB) model in a 16-foot transonic wind tunnel at the Arnold Engineering Development Center (AEDC). The BWB model is a follow-on to previous wind tunnel tests conducted in the National Transonic Facility (NTF). The AEDC wind tunnel's larger cross-section enabled researchers to gather a broader range of data, including measurements of the model taken at higher Mach numbers than the earlier tests had allowed. During testing, researchers investigated both Mach tuck and Mach buffet on the configuration. Mach tuck is a condition wherein the nose of the aircraft tends to pitch downward as the airflow around the wing reaches supersonic speeds. Mach buffet is a condition in which the wings begin to vibrate at supersonic speeds. The research team observed neither condition during the testing, which involved more than 250 data runs, covering 23 configurations and spanning a Mach number range of 0.5 to 0.97. To permit a direct comparison of data, the researchers conducted the initial portion of this test under conditions mirroring those of the NTF tests. The team then performed the remainder of the testing at a lower tunnel air pressure, which is less expensive and thus allows more configurations to be tested. The BWB airframe merges wings and a wind airfoil-shaped body, thereby generating lift and minimizing drag. In addition, it promises greater passenger or cargo capacity. Its potential may extend to various commercial and military applications as well, including tanker or transport aircraft.