Engineering topics

Grafton, Sue B.

Publications and source records attributed to Grafton, Sue B..

5 records

NASA NTRS2014

Enabling Advanced Wind-Tunnel Research Methods Using the NASA Langley 12-Foot Low Speed Tunnel

Design of Experiment (DOE) testing methods were used to gather wind tunnel data characterizing the aerodynamic and propulsion forces and moments acting on a complex vehicle configuration with 10 motor-driven propellers, 9 control surfaces, a tilt wing, and a tilt tail. This paper describes the potential benefits and practical implications of using DOE methods for wind tunnel testing - with an emphasis on describing how it can affect model hardware, facility hardware, and software for control and data acquisition. With up to 23 independent variables (19 model and 2 tunnel) for some vehicle configurations, this recent test also provides an excellent example of using DOE methods to assess critical coupling effects in a reasonable timeframe for complex vehicle configurations. Results for an exploratory test using conventional angle of attack sweeps to assess aerodynamic hysteresis is summarized, and DOE results are presented for an exploratory test used to set the data sampling time for the overall test. DOE results are also shown for one production test characterizing normal force in the Cruise mode for the vehicle.

Busan, Ronald C.↗

NASA NTRS1991

Multiaxis thrust vectoring using axisymmetric nozzles and postexit vanes on an F/A-18 configuration vehicle

A ground-based investigation was conducted on an operational system of multiaxis thrust vectoring using postexit vanes around an axisymmetric nozzle. This thrust vectoring system will be tested on the NASA F/A-18 High Alpha Research Vehicle (HARV) aircraft. The system provides thrust vectoring capability in both pitch and yaw. Ground based data were gathered from two separate tests at NASA Langley Research Center. The first was a static test in the 16-foot Transonic Tunnel Cold-Jet Facility with a 14.25 percent scale model of the axisymmetric nozzle and the postexit vanes. The second test was conducted in the 30 by 60 foot wind tunnel with a 16 percent F/A-18 complete configuration model. Data from the two sets are being used to develop models of jet plume deflection and thrust loss as a function of vane deflection. In addition, an aerodynamic interaction model based on plume deflection angles will be developed. Results from the scale model nozzle test showed that increased vane deflection caused exhaust plume turning. Aerodynamic interaction effects consisted primarily of favorable interaction of moments and unfavorable interaction of forces caused by the vectored jet plume.

Bowers, Albion H.↗

NASA NTRS1989

Aerodynamic Characteristics of a Proposed Personnel Launch System (PLS) Lifting-Body Configuration at Mach Numbers from 0.05 to 20.3

A wind-tunnel investigation was performed to determine the aerodynamic characteristics of a proposed lifting-body personnel launch system (PLS) configuration over a Mach range of 0.05 to 20.3. The test configuration had a low-aspect-ratio body with a flat undersurface and three fins on the upper aft body. Data are presented with a minimum of analysis. All of the experimental data were placed in a structured data base using the R:BASE system and are included on a CD-ROM available with this report.

Cruz, Christopher I.↗

NASA NTRS1989

Aerodynamic Characteristics of a Proposed Personnel Launch System (PLS) Lifting-Body Configuration at Mach Numbers from 0.05 to 20.3. Supplement

A wind-tunnel investigation was performed to determine the aerodynamic characteristics of a proposed lifting-body personnel launch system (PLS) configuration over a Mach range of 0.05 to 20.3. The test configuration had a low-aspect-ratio body with a flat undersurface and three fins on the upper aft body. Data are presented with a minimum of analysis. All of the experimental data were placed in a structured data base using the R:BASE system. This is the CD-ROM that is available for this report.

Cruz, Christopher I.↗

NASA NTRS1988

High-alpha flight dynamics research on the X-29 configuration using dynamic model test techniques

High-angle-of-attack flight dynamics of the X-29 configuration were studied using dynamic model test techniques. These tests identified phenomena including wing rock, spins, and tumbling which dominate the high-alpha behavior of the configuration and define its usable flight envelope. Results of these tests have been used to design flight control concepts to minimize adverse behavior. Planned high-angle-of-attack flight tests of the X-29 airplane will provide an opportunity to validate the model predictions.

Croom, Mark A.↗