Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “SeS”

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.

At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Te4MoW3(SeS)2 by Materials Project

(WTe2)2MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; and two WTe2 sheets oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.56 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In each WTe2 sheet, W+3.33+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4Mo3W(SeS)2 by Materials Project

(MoTe2)2MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction; two MoTe2 sheets oriented in the (0, 0, 1) direction; and one WS2 sheet oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo+4.67+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.56 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In each MoTe2 sheet, Mo+4.67+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. All Te–Mo bond lengths are 2.71 Å. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent Mo+4.67+ atoms. All Te–Mo bond lengths are 2.71 Å. In the WS2 sheet, W2+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W2+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4Mo3W(SeS)2 by Materials Project

WTe2MoTe2MoSe2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one MoSe2 sheet oriented in the (0, 0, 1) direction; one MoTe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo+4.67+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.47 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In the MoSe2 sheet, Mo+4.67+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.56 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In the MoTe2 sheet, Mo+4.67+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. Te2- is bonded in a 12-coordinate geometry to three equivalent Mo+4.67+ atoms. In the WTe2 sheet, W2+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MoW(SeS)2 by Materials Project

WSe2MoSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one MoSe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; and one WSe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.43 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.53 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W2+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.44 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms. In the WSe2 sheet, W2+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.54 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MoW(SeS)2 by Materials Project

WSe2MoSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one MoSe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; and one WSe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. There are three shorter (2.43 Å) and three longer (2.44 Å) Mo–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo6+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. There are three shorter (2.53 Å) and three longer (2.54 Å) Mo–Se bond lengths. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W2+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.44 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms. In the WSe2 sheet, W2+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.54 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo3W(SeS)4 by Materials Project

WSe2MoSe2(MoS2)2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of two MoS2 sheets oriented in the (0, 0, 1) direction; one MoSe2 sheet oriented in the (0, 0, 1) direction; and one WSe2 sheet oriented in the (0, 0, 1) direction. In each MoS2 sheet, Mo+4.67+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.43 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo+4.67+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In the MoSe2 sheet, Mo+4.67+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.53 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In the WSe2 sheet, W2+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.54 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MoW3(SeS)4 by Materials Project

(WSe2)2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; and two WSe2 sheets oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.43 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo6+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.44 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In each WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.54 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4MoW3(SeS)2 by Materials Project

(WTe2)2WSe2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and two WTe2 sheets oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo6+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.56 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In each WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdIn2(SeS)2 by Materials Project

CdIn2S2Se2 is Spinel-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four equivalent S2- atoms to form CdS4 tetrahedra that share corners with twelve equivalent InSe3S3 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cd–S bond lengths are 2.65 Å. In the second Cd2+ site, Cd2+ is bonded to four equivalent Se2- atoms to form CdSe4 tetrahedra that share corners with twelve equivalent InSe3S3 octahedra. The corner-sharing octahedral tilt angles are 59°. All Cd–Se bond lengths are 2.63 Å. In3+ is bonded to three equivalent Se2- and three equivalent S2- atoms to form InSe3S3 octahedra that share corners with six CdS4 tetrahedra and edges with six equivalent InSe3S3 octahedra. All In–Se bond lengths are 2.77 Å. All In–S bond lengths are 2.68 Å. Se2- is bonded to one Cd2+ and three equivalent In3+ atoms to form a mixture of distorted edge and corner-sharing SeCdIn3 trigonal pyramids. S2- is bonded in a distorted rectangular see-saw-like geometry to one Cd2+ and three equivalent In3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MoW(SeS)2 by Materials Project

MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of two MoSe2 sheets oriented in the (0, 0, 1) direction and two WS2 sheets oriented in the (0, 0, 1) direction. In each MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. There are three shorter (2.53 Å) and three longer (2.54 Å) Mo–Se bond lengths. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In each WS2 sheet, W2+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.44 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnCu2Sn(SeS)2 by Materials Project

Cu2ZnSnS2Se2 is Clathrate-derived structured and crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. Cu1+ is bonded to two equivalent Se2- and two equivalent S2- atoms to form CuSe2S2 tetrahedra that share corners with four equivalent CuSe2S2 tetrahedra, corners with four equivalent ZnSe2S2 tetrahedra, and corners with four equivalent SnSe2S2 tetrahedra. Both Cu–Se bond lengths are 2.44 Å. Both Cu–S bond lengths are 2.30 Å. Zn2+ is bonded to two equivalent Se2- and two equivalent S2- atoms to form ZnSe2S2 tetrahedra that share corners with four equivalent SnSe2S2 tetrahedra and corners with eight equivalent CuSe2S2 tetrahedra. Both Zn–Se bond lengths are 2.48 Å. Both Zn–S bond lengths are 2.39 Å. Sn4+ is bonded to two equivalent Se2- and two equivalent S2- atoms to form SnSe2S2 tetrahedra that share corners with four equivalent ZnSe2S2 tetrahedra and corners with eight equivalent CuSe2S2 tetrahedra. Both Sn–Se bond lengths are 2.59 Å. Both Sn–S bond lengths are 2.50 Å. Se2- is bonded to two equivalent Cu1+, one Zn2+, and one Sn4+ atom to form SeZnCu2Sn tetrahedra that share corners with four equivalent SeZnCu2Sn tetrahedra and corners with eight equivalent SZnCu2Sn tetrahedra. S2- is bonded to two equivalent Cu1+, one Zn2+, and one Sn4+ atom to form SZnCu2Sn tetrahedra that share corners with four equivalent SZnCu2Sn tetrahedra and corners with eight equivalent SeZnCu2Sn tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd2GaAg(SeS)2 by Materials Project

AgCd2GaS2Se2 is Clathrate-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Ag1+ is bonded to one Se2- and three S2- atoms to form AgSeS3 tetrahedra that share corners with two equivalent AgSeS3 tetrahedra, corners with four equivalent GaSeS3 tetrahedra, and corners with six CdSe3S tetrahedra. The Ag–Se bond length is 2.64 Å. There are two shorter (2.58 Å) and one longer (2.68 Å) Ag–S bond lengths. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to three Se2- and one S2- atom to form CdSe3S tetrahedra that share corners with three equivalent AgSeS3 tetrahedra, corners with three equivalent GaSeS3 tetrahedra, and corners with six CdSe3S tetrahedra. There are two shorter (2.59 Å) and one longer (2.72 Å) Cd–Se bond lengths. The Cd–S bond length is 2.63 Å. In the second Cd2+ site, Cd2+ is bonded to three Se2- and one S2- atom to form CdSe3S tetrahedra that share corners with three equivalent AgSeS3 tetrahedra, corners with three equivalent GaSeS3 tetrahedra, and corners with six CdSe3S tetrahedra. There are one shorter (2.59 Å) and two longer (2.69 Å) Cd–Se bond lengths. The Cd–S bond length is 2.54 Å. Ga3+ is bonded to one Se2- and three S2- atoms to form GaSeS3 tetrahedra that share corners with two equivalent GaSeS3 tetrahedra, corners with four equivalent AgSeS3 tetrahedra, and corners with six CdSe3S tetrahedra. The Ga–Se bond length is 2.50 Å. There are one shorter (2.29 Å) and two longer (2.47 Å) Ga–S bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Ag1+ and three Cd2+ atoms to form SeCd3Ag tetrahedra that share corners with six SeCd3Ag tetrahedra and corners with six SCdGaAg2 tetrahedra. In the second Se2- site, Se2- is bonded to three Cd2+ and one Ga3+ atom to form SeCd3Ga tetrahedra that share corners with six SeCd3Ag tetrahedra and corners with six SCdGaAg2 tetrahedra. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Ag1+, one Cd2+, and one Ga3+ atom to form SCdGaAg2 tetrahedra that share corners with six SeCd3Ag tetrahedra and corners with six SCdGaAg2 tetrahedra. In the second S2- site, S2- is bonded to one Ag1+, one Cd2+, and two equivalent Ga3+ atoms to form SCdGa2Ag tetrahedra that share corners with six SeCd3Ag tetrahedra and corners with six SCdGaAg2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4Mo3W(SeS)2 by Materials Project

(MoTe2)2MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction; two MoTe2 sheets oriented in the (0, 0, 1) direction; and one WS2 sheet oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo+4.67+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.56 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In each MoTe2 sheet, Mo+4.67+ is bonded to six Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent Mo+4.67+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent Mo+4.67+ atoms. In the WS2 sheet, W2+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W2+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MoW(SeS)2 by Materials Project

MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of two MoSe2 sheets oriented in the (0, 0, 1) direction and two WS2 sheets oriented in the (0, 0, 1) direction. In each MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.53 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In each WS2 sheet, W2+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.44 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2(SeS)3 by Materials Project

ZrSSe2ZrSeS2 crystallizes in the monoclinic Pm space group. The structure is two-dimensional and consists of one ZrSeS2 ribbon oriented in the (0, 1, 0) direction and one ZrSSe2 sheet oriented in the (0, 0, 1) direction. In the ZrSeS2 ribbon, Zr3+ is bonded in a 6-coordinate geometry to two equivalent Se and four S2- atoms. Both Zr–Se bond lengths are 2.76 Å. There are two shorter (2.63 Å) and two longer (2.64 Å) Zr–S bond lengths. Se is bonded in a distorted L-shaped geometry to two equivalent Zr3+ atoms. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Zr3+ and one S2- atom. The S–S bond length is 2.08 Å. In the second S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Zr3+ and one S2- atom. In the ZrSSe2 sheet, Zr3+ is bonded in a 2-coordinate geometry to four Se and two equivalent S2- atoms. All Zr–Se bond lengths are 2.76 Å. Both Zr–S bond lengths are 2.63 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded in a 4-coordinate geometry to two equivalent Zr3+ and two equivalent S2- atoms. There are one shorter (2.23 Å) and one longer (3.20 Å) Se–S bond lengths. In the second Se site, Se is bonded in a distorted L-shaped geometry to two equivalent Zr3+ atoms. S2- is bonded in a 2-coordinate geometry to two equivalent Zr3+ and two equivalent Se atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1989

SES cupola interactive display design environment

The Systems Engineering Simulator, located at the Lyndon B. Johnson Space Center in Houston, Texas, is tasked with providing a real-time simulator for developing displays and controls targeted for the Space Station Freedom. These displays and controls will exist inside an enclosed workstation located on the space station. The simulation is currently providing the engineering analysis environment for NASA and contractor personnel to design, prototype, and test alternatives for graphical presentation of data to an astronaut while he performs specified tasks. A highly desirable aspect of this environment is to have the capability to rapidly develop and bring on-line a number of different displays for use in determining the best utilization of graphics techniques in achieving maximum efficiency of the test subject fulfilling his task. The Systems Engineering Simulator now has available a tool which assists in the rapid development of displays for these graphic workstations. The Display Builder was developed in-house to provide an environment which allows easy construction and modification of displays within minutes of receiving requirements for specific tests.

Vu, Bang Q.↗
NASA NTRS1993

Issac, Jason Cherian ses in transonic flow

Flutter analysis of a two degree of freedom airfoil in compressible flow is performed using a state-space representation of the unsteady aerodynamic behavior. Indicial response functions are used to represent the normal force and moment response of the airfoil. The structural equations of motion of the airfoil with bending and torsional degrees of freedom are coupled to the unsteady air loads and the aeroelastic system so modelled is solved as an eigenvalue problem to determine the stability. The aeroelastic equations are also directly integrated with respect to time and the time-domain results compared with the results from the eigenanalysis. A good agreement is obtained. The derivatives of the flutter speed obtained from the eigenanalysis are calculated with respect to the mass and stiffness parameters by both analytical and finite-difference methods for various transonic Mach numbers. The experience gained from the two degree of freedom model is applied to study the sensitivity of the flutter response of a wing with respect to various shape parameters. The parameters being considered are as follows: (1) aspect ratio; (2) surface area of the wing; (3) taper ratio; and (4) sweep. The wing deflections are represented by Chebyshev polynomials. The compressible aerodynamic state-space model used for the airfoil section is extended to represent the unsteady aerodynamic forces on a generally laminated tapered skewed wing. The aeroelastic equations are solved as an eigenvalue problem to determine the flutter speed of the wing. The derivatives of the flutter speed with respect to the shape parameters are calculated by both analytical and finite difference methods.

Issac, Jason Cherion↗