Issue 10 Volume 41 May 16, 2003

modeling effort will also make strides in improving predictions of steady flow performance of fan and compressor blades at
off-design conditions. This report summarizes the progress and results obtained in the first year of this program. These include:
installation and verification of the operation of the parallel version of TURBO; the grid generation and initiation of steady flow
simulations of the NASA/Pratt&Whitney airfoil at a Mach number of 0.5 and chordal incidence angles of 0 and 10 deg.; and
the investigation of the prediction of laminar separation bubbles on a NACA 0012 airfoil.
Author
Unsteady Aerodynamics; Turbomachinery; Airfoils; Aeroelasticity; Gas Turbine Engines; Incidence; Forced Vibration
20030032493 NASA Glenn Research Center, Cleveland, OH, USA
Strength, Fracture Toughness, and Slow Crack Growth of Zirconia/Alumina Composites at Elevated Temperature
Choi, Sung R.; Bansal, Narottam P.; February 2003; 18 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS-22-708-75-03
Report No.(s): NASA/TM-2003-212108; NAS 1.15:212108; E-13763; No Copyright; Avail: CASI; A03, Hardcopy
Various electrolyte materials for solid oxide fuel cells were fabricated by hot pressing 10 mol% yttria-stabilized zirconia
(10-YSZ) reinforced with two different forms of alumina particulates and platelets each containing 0 to 30 mol% alumina.
Flexure strength and fracture toughness of platelet composites were determined as a function of alumina content at 1000 C
in air and compared with those of particulate composites determined previously. In general, elevated-temperature strength and
fracture toughness of both composite systems increased with increasing alumina content. For a given alumina content, flexure
strength of particulate composites was greater than that of platelet composites at higher alumina contents (greater than or equal
to 20 mol%), whereas, fracture toughness was greater in platelet composites than in particulate composites, regardless of
alumina content. The results of slow crack growth (SCG) testing, determined at 1000 C via dynamic fatigue testing for three
different composites including 0 mol% (10-YSZ matrix), 30 mol % particulate and 30 mol% platelet composites, showed that
susceptibility to SCG was greatest with SCG parameter n=6to8forboth 0 and 30 mol% particulate composites and was
least with n=33forthe30mol% platelet composite.
Author
Fabrication; Fracture Strength; Yttria-Stabilized Zirconia; Zirconium Oxides; Aluminum Oxides; Mechanical Properties;
Crack Propagation; High Temperature
20030032940 NASA Glenn Research Center, Cleveland, OH, USA
Real Gas Effects on the Performance of Hydrocarbon-Fueled Pulse Detonation Engines
Povinelli, Louis A.; Yungster, Shaye; March 2003; 20 pp.; In English; 41st Aerospace Sciences Meeting, 6-9 Jan. 2003, Reno,
NV, USA; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 22-719-10-01
Report No.(s): NASA/TM-2003-212211; E-13819; NAS 1.15:212211; AIAA Paper 2003-0712; ICOMP-2003-02; No
Copyright; Avail: CASI; A03, Hardcopy
This paper presents results for a single-pulse detonation tube wherein the effects of high temperature dissociation and the
subsequent recombination influence the sensible heat release available for providing propulsive thrust. The study involved the
use of ethylene and air at equivalence ratios of 0.7 and 1.0. The real gas effects on the sensible heat release were found to be
significantly large so as to have an impact on the thrust, impulse and fuel consumption of a PDE.
Author
Pulse Detonation Engines; Real Gases; Thermodynamics; Hydrocarbon Fuels; Flow Distribution; Gas Mixtures
20030032968 NASA Glenn Research Center, Cleveland, OH, USA
Mode I, Mode II, and Mixed-Mode Fracture of Plasma-Sprayed Thermal Barrier Coatings at Ambient and Elevated
Temperatures
Choi, Sung R.; Zhu, Dongming; Miller, Robert A.; March 2003; 27 pp.; In English; Eighth International Symposium on
Fracture Mechanics of Ceramics, 25-28 Feb. 2003, Houston, TX, USA; Original contains color illustrations
Contract(s)/Grant(s): WBS-22-714-04-30
Report No.(s): NASA/TM-2003-212185; NAS 1.15:212185; E-13787; Copyright; Avail: CASI; A03, Hardcopy
The mixed-mode fracture behavior of plasma-sprayed ZrO2-8 wt% Y2O3 thermal barrier coatings was determined in air
at 25 and 1316 C in asymmetric four-point flexure with single edge v-notched beam (SEVNB) test specimens. The mode I
fracture toughness was found to be K(sub Ic) = 1.15 plus or minus 0.07 and 0.98 plus or minus 0.13 MPa the square root of
m, respectively, at 25 and 1316 C. The respective mode II fracture toughness values were K(sub IIc) = 0.73 plus or minus 0.10
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