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Fujii, K.

Publications and source records attributed to Fujii, K..

13 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Final Mission and Navigation Design for the 2016 Mars InSight Mission

Project Overview: NASA’s 12th Discovery Program mission that will place a single geophysical lander on Mars to study its deep interior using seismic (tidal, marsquake, and impact), rotational, and thermal measurements -First mission to unveil the composition, structure and thermal state of martian crust, mantle and core; Rebuild of the Phoenix flight system, upgraded with Juno/GRAIL avionics -Phoenix cruise stage: 3-axis stabilized, 3.2 square meter UTJ (Ultra Triple-Junction) solar array, X-band telecom -Phoenix aeroshell (heat shield, backshell, parachute) -Phoenix lander: radar, pulsed thrusters, legs, payload deck, 5.1 square meter UTJ solar arrays, two redundant Li-ion batteries, UHF (Ultra High Frequency)/X-band telecom -Dual string: Internally or functionally-redundant equipment; Science Payload -SEIS (Seismic Experiment for Interior Structure) / CNES (Centre National d’Etudes Spatiales); Three-axis seismometry, to measure seismic waves traveling through the interior -HP3 (Heat Flow and Physical Properties Probe) / DLR (German Aerospace Center) -Subsurface heat probe, to measure the heat flux from the interior - RISE (Rotation and Interior Structure Experiment) / JPL (Jet Propulsion Laboratory) -Radiometric geodesy, to determine precession & nutation of the planet’s rotation axis. 2016 Disclaimer: The InSight launch in 2016 was suspended due to critical issues with the Seismic Experiment for Interior Structure (SEIS) instrument that could not be fixed prior to the planned launch period. This presentation and its corresponding paper represent the state of the design for the 2016 mission. No attempt has been made to reflect the latest developments. [2018 Note: InSight (Mars Lander) was later launched and arrived on Mars on Nov. 26, 2018.]

Abilleira, F.↗
NASA NTRS2000

NSTAR Ion Propulsion

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NSTAR SEP electric propulsion DS1 ion propulsion i↗
NASA NTRS2000

NSTAR Technology Validation

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NSTAR ion propulsion SEP ion engine electric propu↗
NASA NTRS1991

Navier-Stokes Simulation Of Wind-Tunnel Flow

Report describes three-dimensional Navier-Stokes simulation of transonic flow past model wing in wind tunnel and in free air. Numerical integration performed by LU-ADI factorization algorithm. Simulation shows effects of walls of tunnel.

Obayashi, S.↗
NASA NTRS1987

Evaluation of Navier-Stokes and Euler solutions for leading-edge separation vortices

Extensive study on the numerical simulation of the vortical flow over a double delta wing is carried out using the thin layer Navier-Stokes and Euler equations. Two important flow characteristics, vortex interaction and vortex breakdown, are successfully simulated. Grid resolution is one of the most important factors associated with the vortex problem. Computations were performed on a series of grids with various levels of refinement, coarse, medium, and fine. Computations using either the coarse or medium grids fail to capture the proper physical phenomena. The computed result using a fine grid shows flow unsteadiness once the vortex breakdown takes place. The C sub L - alpha characteristics are well predicted up to the breakdown angle of attack for all the grid distributions. The Euler solutions show fairly good agreement with the experiment on the C sub L - alpha characteristics. However, other aspects of the solution at each angle of attack, such as the locus of the leading edge separation vortex, are not consistent with the experiment. Even for the fine grid Navier-Stokes computations, further grid resolution is required to obtain good quantitative agreement with the experiment.

Fujii, K.↗
NASA NTRS1987

Evaluation of Navier-Stokes and Euler solutions for leading-edge separation vortices

Extensive study on the numerical simulation of the vortical flow over a double delta wing is carried out using the thin layer Navier-Stokes and Euler equations. Two important flow characteristics, vortex interaction and vortex breakdown, are successfully simulated. Grid resolution is one of the most important factors associated with the vortex problem. Computations were performed on a series of grids with various levels of refinement, coarse, medium, and fine. Computations using either the coarse or medium grids fail to capture the proper physical phenomena. The computed result using a fine grid shows flow unsteadiness once the vortex breakdown takes place. The C sub L - alpha characteristics are well predicted up to the breakdown angle of attack for all the grid distributions. The Euler solutions show fairly good agreement with the experiment on the C sub L - alpha characteristics. However, other aspects of the solution at each angle of attack, such as the locus of the leading edge separation vortex, are not consistent with the experiment. Even for the fine grid Navier-Stokes computations, further grid resolution is required to obtain good quantitative agreement with the experiment.

Fujii, K.↗
NASA NTRS1984

Numerical simulation of the viscous flow fields over three-dimensional complicated geometries

A 'thin-layer' Navier-Stokes code capable of predicting steady state viscous flows is applied to complicated three-dimensional flow fields. The code is written in a generalized coordinate system, and a recently developed grid generation procedure is used for the flow-field discretization. Application is made to the vortical flow over a delta wing at high angle of attack, and the computed results are compared with experimental results. The results indicate that the present method can capture the physical phenomenon well. It is observed that a leading-edge separation vortex is formed over the wing, as is a secondary separation vortex near the leading edge. The flow field behind the trailing edge is also well described. Application is also made to the transonic flow over the Shuttle configuration. The result appears to be reasonable even though no experimental data are available for comparison. These results indicate that the present approach is capable of computing complicated three-dimensional flow fields.

Fujii, K.↗
NASA NTRS1984

Viscous transonic flow computation over Space Shuttle configuration

A thin-layer Navier-Stokes code capable of predicting steady-state viscous flows is applied to the transonic flow over a Space Shuttle configuration. The code is written in the generalized coordinate system, and the grid-generation code of Fujii (1983) is used for the discretization of the flow field. The flow-field computation is done using the CRAY 1S computer at NASA Ames. The computed result is physically reasonable, even though no experimental data is available for the comparison purpose.

Fujii, K.↗
NASA NTRS1983

Solution of Poisson equations for 3-dimensional grid generations

A method for generating three dimensional, finite difference grids about complicated geometries by using Poisson equations is developed. The inhomogenous terms are automatically chosen such that orthogonality and spacing restrictions at the body surface are satisfied. Spherical variables are used to avoid the axis singularity, and an alternating-direction-implicit (ADI) solution scheme is used to accelerate the computations. Computed results are presented that show the capability of the method. Since most of the results presented have been used as grids for flow-field computations, this is indicative that the method is a useful tool for generating three-dimensional grids about complicated geometries.

Fujii, K.↗
NASA NTRS1983

Computations of two-phase supersonic nozzle flows by a space-marching method

A practical method for efficiently analyzing the two-phase flow field in the supersonic region of an axisymmetric rocket nozzle is presented. The governing hyperbolic equations for the gas- and particle-phases are simultaneously integrated downstream using a space-marching procedure. Both one- and two-phase flow computations are performed for the JPL axisymmetric nozzle. The results show the nonequilibrium effects which are due to the existence of particles in the flow. The comparisons with the experimental data and other numerical solutions are made to examine the accuracy of the present method.

Fujii, K.↗
NASA NTRS1983

Numerical simulation of the leading-edge separation vortex for a wing and strake-wing configuration

In the present investigation, the 'thin layer' Navier-Stokes equations are used to compute the flow about a delta wing and a strake-delta wing configuration. Both configurations possess blunt noses and rounded leading edges. The computational grid about these configurations is generated using a newly developed three-dimensional grid-generation code which solves a set of Poisson equations with spherical coordinate variables using an alternating direction implicit (ADI) scheme. Computational results are obtained for an isolated wing with 60 deg sweep and a strake-wing configuration with 80-60 deg sweep. Computations for angles of attack in the range from 6 to 30 deg are presented. Attention is given to the effect of the angle of attack, the Mach number, and the Reynolds number. Theoretical results are compared with experimental data.

Fujii, K.↗
NASA NTRS1975

ATS-5 observations of plasma sheet particles before the expansion-phase onset, appendix C.

Behavior of the plasma sheet around its earthward edge during substorms was studied by using high resolution (every 2.6 sec) measurements of proton and electron fluxes by ATS-5. In the injection region near midnight the flux increase at the expansion-phase onset is shown to lag behind the onset of the low-latitude positive bay by several minutes. Depending upon the case, before the above increase (1) the flux stays at a constant level, (2) it gradually increases for some tens of minutes, or (3) it briefly drops to a low level. Difference in the position of the satellite relative to the earthward edge and to the high-latitude boundary of the plasma sheet is suggested as a cause of the above difference in flux variations during the growth phase of substorms. Magnetograms and tables (data) are shown.

Fujii, K.↗