NASA Scientific and Technical Aerospace Reports

20040068170 NASA Ames Research Center, Moffett Field, CA, USA
CFD Support for STS-107 Ascent Investigation
Rogers, Stuart E.; Gomez, Reynaldo J.; Vicker, Darby; Aftosmis, Michael J.; Meakin, Robert; Chan, William M.; Murman,
Scott; 2004; 24 pp.; In English; 42nd AIAA Aerospace Sciences Meeting, 5-8 Jan. 2004, Reno, NV, USA; No Copyright;
Avail: CASI; A03, Hardcopy
The research described in this viewgraph presentation investigates the ascent of STS-107 and foam-debris impact, and
contributes to understanding of the STS-107 accident using CFD tools. The goals of the research are to: 1) Quantify loads on
foam bipod ramp during ascent; 2) Provide steady-state flow-fields to debris-transport simulations; 3) Simulate flight of foam
debris using unsteady six-degree-of-freedom calculations; 4) Provide estimates of foam mass, velocity, and impact angle
which correlate with video and film evidence.
Derived from text
Computational Fluid Dynamics; Columbia (Orbiter); Accident Investigation
20040068181 NASA Ames Research Center, Moffett Field, CA, USA
Comparison of Artificial Compressibility Methods
Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan; 2003; 2 pp.; In English; ICCFD3 Conference, 12-16 Jul. 2004, Toronto,
Canada; No Copyright; Avail: CASI; A01, Hardcopy
Various artificial compressibility methods for calculating three-dimensional, steady and unsteady, laminar and turbulent,
incompressible Navier-Stokes equations are compared in this work. Each method is described in detail along with appropriate
physical and numerical boundary conditions. Analysis of well-posedness and numerical solutions to test problems for each
method are provided. A comparison based on convergence behavior, accuracy, stability and robustness is used to establish the
relative positive and negative characteristics of each method.
Author
Methodology; Numerical Analysis; Robustness (Mathematics); Incompressible Flow
20040068185 NASA Ames Research Center, Moffett Field, CA, USA
Automated Parameter Studies Using a Cartesian Method
Murman, Scott M.; Aftosimis, Michael J.; Nemec, Marian; 2004; 13 pp.; In English; 22nd AIAA Applied Aerodynamics
Conference, 16-19 Aug. 2004, Providence, RI, USA; No Copyright; Avail: CASI; A03, Hardcopy
Computational Fluid Dynamics (CFD) is now routinely used to analyze isolated points in a design space by performing
steady-state computations at fixed flight conditions (Mach number, angle of attack, sideslip), for a fixed geometric
configuration of interest. This "point analysis" provides detailed information about the flowfield, which aides an
engineer in understanding, or correcting, a design. A point analysis is typically performed using high fidelity methods at a
handful of critical design points, e.g. a cruise or landing configuration, or a sample of points along a flight trajectory.
Author
Computational Fluid Dynamics; Mach Number; Flow Distribution; Flight Conditions
20040068211 NASA Goddard Space Flight Center, Greenbelt, MD, USA
Arrays of High Performance Thermal Detectors
Moseley, Harvey; International Thermal Detectors Workshop (TDW 2003); February 2004, pp. 2-15; In English; See also
20040068186; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document
Thermal detectors have historically been the sensors of choice for applications where photoconductive or photovoltaic
detectors are unavailable. While they have the advantage of broad wavelength coverage, a primary disadvantage has been
sensitivity; at a given operating temperature, bolometers are typically much less sensitive than photodetectors. The
development of cryogenic bolometers has resulted in thermal detectors which can reach fundamental sensitivity limits. When
operated at temperatures below 0.3 K these devices can provide background-limited sensitivity for cryogenic imaging and
spectroscopy in space. The past decade has seen a rapid growth in sensitivity and array format in cryogenic bolometers.
Micromachining technology, combined with advances in superconducting electronics, provides a strong technological base for
future developments. I will describe the present state of development of low-temperature thermal detectors, and the possible
extension of this technology to higher temperature operation.
Author
Imaging Techniques; Photoconductivity; Superconductivity; Bolometers; Cryogenics
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