Adaptive Refinement Tools for Tetrahedral Unstructured Grids

This software can potentially be used in aerospace, aviation, and automotive applications. NASA’s Langley Research Center engineers have developed a new software package for more facile computational fluid dynamics. The software’s fast user run time, robustness, and efficiency have enabled its extensive use in space shuttle modeling. Adaptive Refinement Tool (ART) permits the computational modeling of flow, including jet or rocket plumes, wakes, and shocks via unstructured tetrahedral grids. Commercially available software packages often struggle to sufficiently and quickly model such complex examples of flow. ART also allows cells to be divided into two, four, or eight cells as compared to traditional software, which allows cell division only in units of eight. This is advantageous as it allows the user to control cell division more succinctly. ART executes commands via colloquial English, and has built-in internal statistical programming that increases its ease of use. ART allows the user the choice of alternate variables such as temperature or pressure at will, which facilitates modeling unusual or unlikely occurrences.

Posted in: Briefs, Software, Computational fluid dynamics, Computer software and hardware


Self-Stabilizing, Byzantine-Fault-Tolerant Clock Synchronization System and Method

Initially developed for wired applications, the technology could also be applied to wireless systems. NASA’s Langley Research Center has developed a portfolio of technologies regarding clock synchronization in distributed systems. Distributed synchronous systems that need to provide globally coordinated operations require each component (node) in the system to be precisely synchronized. Such systems could include electronic components within an aircraft or automobile, or large-scale networks of components that communicate with each other (e.g. multiple aircraft or automobiles). NASA’s technologies provide for very quick synchronization while tolerating various faults. These protocols provide distributed autonomous synchronization (i.e. no master clock signal required) and do not rely on any assumptions regarding the initial state of the system or internal status of the nodes.

Posted in: Briefs, Software, Calibration, Communication protocols, Electronic control systems


Method of Performing Computational Aeroelastic Analyses

This technology can be used for dynamic behavioral models of large buildings, bridges, dams, and towers. NASA’s Langley Research Center has developed unsteady aerodynamic Reduced-Order Models (ROMs) that significantly improve computational efficiency compared to traditional analyses of aeroelastic and other complex and unsteady systems. Traditional methods rely on the repetitive use of aeroelastic computational fluid dynamics (CFD) codes, and the iteration between the structural and nonlinear aerodynamic models of the aeroelastic CFD code for predicting the aeroelastic response of flight vehicles is very time-consuming and computationally expensive. The new ROMs are quite different from the traditional aeroelastic analysis tools, and enable the computational aeroelastic analysis of flight vehicles at a fraction of the time and cost.

Posted in: Briefs, Software, Mathematical models, Aerodynamics


Fourier Transform Spectrometer Performance Modeling

This software models the performance of a Fourier transform spectrometer (FTS). More specifically, it is able to add a number of noise/error sources to the interferogram and transform the errors back to the spectral domain.

Posted in: Briefs, Software, Finite element analysis, Computer software and hardware, Spectroscopy, Noise


Mesh Adaptation Module for Cartesian Meshes with Embedded Boundaries

Future applications include rapid prototyping, computer-based imaging and visualization, and semiconductor device modeling. This work extends the mesh generation capability of NASA’s Cart3D flow simulation software package to permit cell-by-cell mesh enrichment. Cart3D allows users to perform automated Computational Fluid Dynamics (CFD) analysis on a complex geometry. It includes utilities for geometry import, surface modeling and intersection, mesh generation, flow simulation, and post-processing of results. Geometry enters into Cart3D in the form of surface triangulations that may be generated from within Computer-Aided Design (CAD) packages, from legacy surface triangulations, or from structured surface grids. Cart3D uses adaptively refined Cartesian grids to discretize the space surrounding geometry, and cuts the geometry out of the set of cut-cells that actually intersects the surface triangulation.

Posted in: Briefs, Software, CAD, CAM, and CAE, Computational fluid dynamics


Improved Digital Map Rendering Method

Software for aeronautics collision avoidance can be used in aerospace satellites, automobiles, scientific research, marine charting systems, and medical devices. Armstrong Flight Research Center, Edwards, California Data adaptive algorithms are the critically enabling technology for automatic collision avoidance system efforts at NASA’s Armstrong Flight Research Center. These Armstrong-developed algorithms provide an extensive and highly efficient encoding process for global-scale digital terrain maps (DTMs) along with a real-time decoding process to locally render map data. Available for licensing, these terrain-mapping algorithms are designed to be easily integrated into an aircraft’s existing onboard computing environment, or into an electronic flight bag (EFB) or mobile device application. In addition to its use within next-generation collision avoidance systems, the software can be adapted for use in a wide variety of applications, including aerospace satellites, automobiles, scientific research, marine charting systems, and medical devices.

Posted in: Briefs, Software, Mathematical models, Aircraft displays, Architecture, Terrain, Collision avoidance systems


Interactive Diagnostic Modeling Evaluator

Ames Research Center, Moffett Field, California NASA’s Ames Research Center has developed an interactive diagnostic modeling evaluator (i-DME) tool to aid in modeling for noise and lag in the data and debugging of system models when fault detection, isolation, and recovery results are incorrect. i-DME is designed to dramatically speed up the modeling debugging process. Often what hinders human-led model developments are 1) the sheer size of playback files, 2) the modeling for noise and lag in the data, and 3) debugging the fault/test relationships in the model. To alleviate these problems, i-DME can automatically play back very large data sets to find time points of interest where userset performance criteria for detection and isolation are violated. i-DME modifies the diagnostic model through its abstract representation, diagnostic matrix (D-matrix). The types of modifications are procedures ranging from modifying 0s and 1s in the D-matrix, adding/removing the rows/columns, or modifying test/wrapper logic used to determine test results. This software has the capacity to be applied to any complex system for navigation or generation of large amounts of complex data to identify, prioritize, and resolve errors in a self-correcting manner.

Posted in: Briefs, Software, Scale models, Computer software and hardware, On-board diagnostics, On-board diagnostics (OBD)


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