The primary objective of this work was to develop and demonstrate a process for accurate and efficient uncertainty quantification and certification prediction of low-boom, supersonic, transport aircraft. High-fidelity computational fluid dynamics models of multiple low-boom configurations were investigated including the Lockheed Martin SEEB-ALR body of revolution, the NASA 69 • Delta Wing, and the Lockheed Martin 1021-01 configuration. A nonintrusive polynomial chaos surrogate modeling approach was used for reduced computational cost of propagating mixed, inherent (aleatory) and model-form (epistemic) uncertainty from both the computation fluid dynamics model and the near-field to ground level propagation model. A methodology has also been introduced to quantify the plausibility of a design to pass a certification under uncertainty. Results of this study include the analysis of each of the three configurations of interest under inviscid and fully turbulent flow assumptions. A comparison of the uncertainty outputs and sensitivity analyses between the configurations is also given. The results of this study illustrate the flexibility and robustness of the developed framework as a tool for uncertainty quantification and certification prediction of low-boom, supersonic aircraft.
A detailed uncertainty analysis for the Ares I ascent aero 6-DOF wind tunnel database is described. While the database itself is determined using only the test results for the latest configuration, the data used for the uncertainty analysis comes from four tests on two different configurations at the Boeing Polysonic Wind Tunnel in St. Louis and the Unitary Plan Wind Tunnel at NASA Langley Research Center. Four major error sources are considered: (1) systematic errors from the balance calibration curve fits and model + balance installation, (2) run-to-run repeatability, (3) boundary-layer transition fixing, and (4) tunnel-to-tunnel reproducibility. Nomenclature A101Ares This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States.https://ntrs.nasa.gov/search.jsp?R=20080024105 2018-05-11T10:44:17+00:00Z Their primary differences are in the launch abort system, the blast shield covering the Orion Command Module, and the various protuberances. The identifiers for those configurations that are used in this paper are A101 for an earlier configuration and A103 for the current configuration. The designs are sufficiently different that the aerodynamics changes must be accounted for in the database. An artist's sketch of the current configuration at launch is shown in Figure 1. Note that there are three first-order loading regions for longitudinal aerodynamics: (1) crew capsule/service module, (2) interstage, and (3) aft skirt. Each protuberance creates a loading region which is secondorder for longitudinal aerodynamics, but which is first-order for lateral-directional aerodynamics.Each configuration was tested at the Boeing Polysonic blow-down wind tunnel (PSWT) for the Mach range, . The PSWT testing was conducted in the transonic test section which is four-foot square and has porous walls. Each configuration was also tested at the NASA Langley Research Center Unitary Plan Wind Tunnel (UPWT) for the Mach range, 1.6. The UPWT tests were conducted in two test sections: test section 1 for and test section 2 for 2.5 0.5The UPWT is continuous flow and both test sections have solid walls four-foot square. The PSWT tests used the NTF-107 force balance while the UPWT tests used the UT-39B balance. The full-scale calibration ranges (same as the maximum loading ranges) for the balances are given in Table 1. Also, given in Table 1 are the standard errors derived from the calibration curve-fit residuals. For all four tests, the force balances were attached to a straight sting which was attached to a roll motor and then to the tunnel mounting system. Base and cavity pressures were measured to correct them to free stream . Both pitch runs at constant zero roll angle and roll runs at constant pitch angles were obtained. The PSWT tests used continuous pitch and roll with data acquisition (digitization) at 100 frames a second that was post-processed with a digital filter at 20 Hz. The UPWT tests used pitch-pause and roll-pause data acquisition, acquiring data at 30 frames per se...
The effort to redesign the packaging and deployment schedule for the parachute system was called the Integrated Design Assessment Team, and the resulting changes to the CM vehicle are generically called the IDAT geometry.
Nomenclature
This paper provides an overview of recent wind tunnel tests performed at the NASA Langley Research Center where the Background-Oriented Schlieren (BOS) technique was used to provide information pertaining to flowfield density disturbances. The facilities in which the BOS technique was applied included the National Transonic Facility (NTF), Transonic Dynamics Tunnel (TDT), 31-Inch Mach 10 Air Tunnel, 15-Inch Mach 6 High-Temperature Air Tunnel, Rotor Test Cell at the 14×22 Subsonic Tunnel, and a 13-Inch Low-Speed Tunnel.
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