Wind tunnel study of wake downwash behind A 6% scale model B1-B aircraft

Technical Report · Tue May 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6839285· OSTI ID:6839285

Strickland, J H; Tadios, E L; Powers, D A

Parachute system performance issues such a turnover and wake recontact may be strongly influenced by velocities induced by the wake of the delivering aircraft, especially if the aircraft is maneuvering at the time of parachute deployment. The effect of the aircraft on the parachute system is a function of the aircraft size, weight, and flight path. In order to provide experimental data for validation of a computer code to predict aircraft wake velocities, a test was conducted in the NASA 14 {times} 22 ft wind tunnel using a 5.78% model of the B-1B strategic bomber. The model was strut mounted through the top of its fuselage by a mechanism which was capable of pitching the model at moderate rates. In this series of tests, the aircraft was pitched at 10{degree}/sec from a cruise angle of attack of 5.3{degree} to an angle of attack of 11{degree} in order to simulate a 2.2g pullup. Data were also taken for the subsequent pitch down sequence back to the cruise angle of attack. Instantaneous streamwise and vertical velocities were measured in the wake at a number of points using a hot wire anemometer. These data have been reduced to the form of downwash coefficients which are a function of the aircraft angle of attack time-history. Unsteady effects are accounted for by use of a wake convection lag-time correlation. 12 refs., 59 figs., 4 tabs.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6839285
• Report Number(s): SAND-90-0008; ON: DE90011783
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
42 ENGINEERING
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
AIRCRAFT
AIR FLOW
PARACHUTES
OPERATION
SCALE MODELS
PERFORMANCE TESTING
ALIGNMENT
COMPILED DATA
FAILURE MODE ANALYSIS
HAZARDS
ORIENTATION
PROBES
RISK ASSESSMENT
TURBULENCE
VELOCITY
WIND TUNNELS
DATA
FLUID FLOW
GAS FLOW
INFORMATION
NUMERICAL DATA
STRUCTURAL MODELS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING
TUNNELS
UNDERGROUND FACILITIES
320201* - Energy Conservation
Consumption
& Utilization- Transportation- Air & Aerospace
420400 - Engineering- Heat Transfer & Fluid Flow
450000 - Military Technology
Weaponry
& National Defense