SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
NdTl is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Nd is bonded in a body-centered cubic geometry to eight equivalent Tl atoms. All Nd–Tl bond lengths are 3.39 Å. Tl is bonded in a body-centered cubic geometry to eight equivalent Nd atoms.
NdTl(WO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Nd3+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.39–2.84 Å. W6+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of W–O bond distances ranging from 1.83–2.17 Å. Tl1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Tl–O bond distances ranging from 2.96–3.19 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent W6+ and two equivalent Tl1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nd3+, one W6+, and one Tl1+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+, two equivalent W6+, and one Tl1+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+, one W6+, and one Tl1+ atom.
TlNd(PO3)4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.39–2.51 Å. Tl1+ is bonded in a 3-coordinate geometry to eleven O2- atoms. There are a spread of Tl–O bond distances ranging from 2.84–3.60 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, two equivalent Tl1+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nd3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Tl1+ and two P5+ atoms. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Tl1+ and two P5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Tl1+ and two P5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+, one Tl1+, and one P5+ atom.
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
The objective of the Hybrid Thermally Efficient Core (HyTEC) – Advanced High Pressure Turbine (HPT) Aerodynamics project is to develop technology for a compact core that contributes to significant fuel burn reductions of 5-10% over current generation technologies. To accomplish this, the HPT is incorporating a range of aerodynamic features and technologies to improve component efficiency and provide favorable systems level trades. In particular, this project explored low solidity airfoils, advanced tip treatments, platform contouring, and advanced ceramic matrix composite (CMC) Stage 2 Nozzle (S2N) airfoils to eliminate the need for post throat cooling in a compact core environment. The maturation of these technology areas is expected to provide a significant improvement in component efficiencies, and consequently reductions in fuel burn, over the current state of the art (SoA). To mature these technologies to Technology Readiness Level (TRL) 4, a test campaign was performed that consisted of four tests at three facilities. TRL 3 testing was performed in the CW22 linear cascade at NASA Glenn for blade and nozzle technologies, TRL 4 nozzle testing was performed at GE Aerospace (GEA) Test Cell A8, and TRL 4 blade testing was performed at the Notre Dame Turbomachinery Laboratory (NDTL) using the Transonic Research Turbine (TRT) rig. Low solidity was successfully demonstrated to a TRL 4 level. Low solidity nozzles showed benefits in line with pre-project expectations, while low solidity blades were shown to have an aerodynamic penalty. Crucially, this program only considered the aerodynamic losses, and systems trades such as reductions in cooling flows are expected to continue to make low solidity blades a net positive. By successfully quantifying the aerodynamic performance in this project, these trades can be conducted to determine where in the engine architecture low solidity blades will contribute positively to system operation. Platform contouring was demonstrated to a TRL 4 level, with performance in line with the lower end of the pre-project expected range. Advanced tip treatments performance levels were indeterminate, showing the expected improvements to flow physics but with a performance level confounded by several rig issues including whirl mode induced variation in tip clearance. The elimination of post-throat cooling on the S2N was successfully demonstrated to provide a performance benefit, however that benefit was approximately half the level that was expected in pre-project predictions. Overall, the technology maturation plan for HyTEC Phase 1 was successful, bringing the suite of technologies to TRL 4.