NASA Scientific and Technical Aerospace Reports

slot in an orientation most nearly opposed to the approaching primary flow. Thrust edliciency, as measured by changes in
nozzle thrust coefficient, was highest at high nozzle pressure ratios, NPR. The static test results agreed with predictions
obtained prior from PABSD, a fully viscous computational fluid dynamics program. Since use of such an injection system on
gas turbine engine exhaust nozzles would be primarily at high NPRs, it was concluded that fluidic control holds promise for
reducing nozzle weight and complexity on future systems.
Author
Fluidics; Nozzle Flow; Computational Fluid Dynamics; Convergent-Divergent Nozzles; Control Theory; Transonic Wind
Tunnels
20040111308 NASA Langley Research Center, Hampton, VA, USA
Hyper-X Hot Structures Comparison of Thermal Analysis and Flight Data
Amundsen, Ruth M.; Leonard, Charles P.; Bruce, Walter E., III; [2004]; 24 pp.; In English; Fifteenth Annual Thermal and
Fluids Analysis Workshop, 29 Aug. - 3 Sep. 2004, Pasadena, CA, USA
Contract(s)/Grant(s): 23-745-30-20
Report No.(s): Paper 109-A0016; No Copyright; Avail: CASI; A03, Hardcopy
The Hyper-X (X-43A) program is a flight experiment to demonstrate scramjet performance and operability under
controlled powered free-flight conditions at Mach 7 and 10. The Mach 7 flight was successfully completed on March 27, 2004.
Thermocouple instrumentation in the hot structures (nose, horizontal tail, and vertical tail) recorded the flight thermal response
of these components. Preflight thermal analysis was performed for design and risk assessment purposes. This paper will
present a comparison of the preflight thermal analysis and the recorded flight data.
Derived from text
Supersonic Combustion Ramjet Engines; Hypersonic Speed; Temperature Effects; Thermal Analysis
20040111314 NASA Langley Research Center, Hampton, VA, USA
Aerodynamic Performance Predictions of Single and Twin Jet Afterbodies
Carlson, John R.; Pao, S. Paul; Abdol-Hamid, Khaled S.; Jones, William T.; [1995]; 11 pp.; In English
Report No.(s): AIAA Paper 95-2622; Copyright; Avail: CASI; A03, Hardcopy
The multiblock three-dimensional Navier-Stokes method PAB3D was utilized by the Component Integration Branch
(formerly Propulsion Aerodynamics Branch) at the NASA-Langley Research Center in an international study sponsored by
AGARD Working Group #17 for the assessment of the state-of-the-art of propulsion-airframe integration testing techniques
and CFD prediction technologies. Three test geometries from ONERA involving fundamental flow physics and four
geometries from NASA-LaRC involving realistic flow interactions of wing, body, tail, and jet plumes were chosen by the
Working Group. An overview of results on four (1 ONERA and 3 LaRC) of the seven test cases is presented. External static
pressures, integrated pressure drag and total drag were calculated for the Langley test cases and jet plume velocity profiles and
turbulent viscous stresses were calculated for the ONERA test case. Only selected data from these calculations are presented
in this paper. The complete data sets calculated by the participants will be presented in an AGARD summary report. Predicted
surface static pressures compared favorably with experimental data for the Langley geometries. Predicted afterbody drag
compared well with experiment. Predicted nozzle drag was typically low due to over-compression of the flow near the trailing
edge. Total drag was typically high. Predicted jet plume quantities on the ONERA case compared generally well with data.
Author
Afterbodies; Computational Fluid Dynamics; Multiblock Grids; Performance Prediction; Three Dimensional Flow; Single
Engine Aircraft; Transonic Wind Tunnels
20040111316 NASA Langley Research Center, Hampton, VA, USA
Effect of Far-Field Boundary Conditions on Boundary-Layer Transition
Bertolotti, Fabio P.; Joslin, Ronald D.; [1995]; 17 pp.; In English
Contract(s)/Grant(s): NAS1-19480; Copyright; Avail: CASI; A03, Hardcopy
The effect of far-field boundary conditions on the evolution of a finite-amplitude two-dimensional wave in the Blasius
boundary layer is assessed. With the use of the parabolized stability equations (PSE) theory for the numerical computations,
either asymptotic, Dirichlet, Neumann or mixed boundary conditions are imposed at various distances from the wall. The
results indicate that asymptotic and mixed boundary conditions yield the most accurate mean-flow distortion and unsteady
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