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The Traffic Situation Display (TSD) is an integrated display of air traffic, weather, terrain, and special use airspace. TSD was designed to serve as a primary graphical interface for ground operators/dispatchers supporting research simulation of single pilot and/or reduced crew operations. One key feature is the seamless transitional flow between the ego-referenced and position-referenced frames.

BL2D: An efficient and fourth-order accurate method to compute two-dimensional and axisymmetric boundary layers on aerospace vehicle wings from low-speed to hypersonic speeds. Aerospace applications include boundary-layer stability analysis, transonic wing design, laminar flow wing design.

GFR is a high-order computational fluid dynamics (CFD) Fortran code for large-eddy simulations. It is based on the simple and efficient flux reconstruction method and accurate to an arbitrary order through an user-supplied input parameter. It is currently capable of using unstructured grids containing quadrilateral or hexahedra elements.

The Macro for an Apriori Grid NUmeric Metric (MAGNUM) software is a Tecplot {TM} macro that computes a grid quality metric, or number, for structured surface and volume grids that identifies how good the grid is for computational science applications. A good measure ranges from 0.7 to 1.0, where 0.7 is acceptable and 1.0 is excellent quality. The macro utilizes grid analysis tools in Tecplot's computational fluid dynamics (CFD) analyzer in conjunction with the analysis presented in AIAA paper 2004-0612.

PLOT3D is a computer graphics program designed to visualize the grid and solutions of structured computational fluid dynamics (CFD) datasets. Version 4.1 uses the OpenGL/GLUT graphics library. Several new features have been added to the code. These include: automatic computation of grid coordinate minimum/maximum; an orphan point plotting function; the ability to read double-precision unformatted data; negative grid index processing; random specification of colors for different walls; and simultaneous specification of walls and subsets for all zones.

ARC2D is a computational fluid dynamics program developed at the NASA Ames Research Center specifically for two-dimensional airfoil and simply connected geometries. The program uses implicit finite-difference techniques to solve two-dimensional Euler equations and Navier-Stokes equations. It is based on the Beam and Warming implicit approximate factorization algorithm in generalized coordinates. The methods are either time accurate or accelerated non-time accurate steady state schemes. The evolution of the solution through time is physically realistic; good solution accuracy is dependent on mesh spacing and boundary conditions.

The Multi-Level Monte Carlo with Python (MLMCPy) software package is code written in Python to solve uncertainty propagation problems. Multi-level Monte Carlo (MLMC) is an efficient alternative to standard Monte Carlo simulation for estimating expectations of outputs to computational models with uncertain input parameters. MLMC greatly reduces computational cost by performing most simulations with low accuracy at a correspondingly low cost, with relatively few simulations being performed at high accuracy and high cost. MLMCPy is a parallel, efficient, and modular implementation of the MLMC method that provides a straightforward means of applying the method to general uncertainty propagation problems.

A simulation of air traffic movement on an airport surface, SOSS can be used in developing, analyzing, and testing runway schedulers and resolution algorithms.

Photographic gallery type application containing imagery and descriptions from the GRC image archive. Photos and data cover the period from 1941-1979. The software has been compiled and bundled as an iOS app for the iPad and intended for release through the Apple App Store.

The X-Plane Connect Toolbox enables users to receive real-time information on one or more simulated vehicles state from the X-Plane flight simulator, and control vehicles running in the X-Plane simulation environment. The toolbox can be used to record simulated flight data, visualize flight profiles, create out-the-window visuals, test autopilots, and test control algorithms. Additionally, the toolbox enables the display of ghost traffic flying predefined flight paths in the simulated airspace, and the visualization of flight plans in the form of waypoints. The toolbox allows custom built or third party autopilot programs to interface with X-Plane through MATLAB, C, C , Java, or Python . Code examples are included in the open source distribution. The toolbox uses a network communication protocol, allowing X-Plane and the client program to run on different computers.

GridEx is an interactive software system developed by Geometry Laboratory of the NASA Langley Research Center for the generation of unstructured meshes. The software integrates native CAD geometry access, multiple unstructured meshing algorithms, and interactive 3D computer graphics through a Graphical User Interface (GUI) resulting in a package that is both powerful and easy to use.

This software was developed to solve Reynolds-averaged Navier-Stokes Equations to simulate turbulent, viscous flows over three-dimensional configurations. A general multiblock grid is used to model complex configurations. A multi-stage Runge-Kutta pseudo-time stepping scheme is coupled with residual smoothing and multigrid acceleration techniques to form an efficient algorithm. TLNS3D-MB was the first CFD code to demonstrate grid independent convergence rate for transonic viscous flows over wing/fuselage configurations.

<p>The aerospace industry uses model aircraft simulation systems to demonstrate and evaluate new computer hardware and software components for flight operations. Formal methods--mathematically based techniques--are used for verification and validation of new systems prior to implementation. By integrating and simulating new tools and methods in model flight control and air transportation systems, flight researchers provide the robust validation tools necessary for commercial system development.</p> <p>Developed at NASA's Armstrong Flight Research Center, the Quad TCM Simulation is a non-proprietary, non-sensitive aircraft Simulink&reg; flight-control-system-oriented model in MATLAB&reg; format. Derived from the TCM developed at NASA's Langley Research Center, Armstrong's Quad TCM Simulation components include flight control computers, sensors, actuators, and interconnects. Component models are the original TCM components with modifications to account for their multichannel nature, to allow for replacement with like components, and to enable testing and evaluation.</p> <p>BENEFITS</p> <p> * Non-proprietary and non-sensitive: Imposes no restrictions on reporting results</p> <p> * Ready to use: Fully integrated with flight control laws, redundancy management, multichannel interconnects, and transport class aircraft simulation</p> <p> * Easily modified: Enables flight control laws to be readily modified--including introduction of faults--thanks to the MATLAB Simulink environment</p> <p> * Speeds technology transfer: Accelerates dissemination and commercial acceptance of formal-methods-compliant tools and techniques</p> <p>APPLICATIONS</p> <p>This software is ideal for control research in realistic multichannel flight controls. In addition, it helps with learning about the complex effects of multichannel flight systems, including failure modes and effects, flight control system performance, etc. It is also useful for general simulation projects and flight system testing.</p> <p>MATLAB and Simulink are registered trademarks of The MathWorks, Inc.</p>

The Flight Optimization System (FLOPS) is a multidisciplinary system of computer programs for conceptual and preliminary design and evaluation of advanced aircraft concepts. It consists of six primary modules: 1) weights, 2) aerodynamics, 3) propulsion data scaling and interpolation, 4) mission performance, 5) takeoff and landing, and 6) program control.

The purpose of this software is to facilitate the creation of analysis and design processes for the conceptual-level aircraft configurations. At its core, the software contains a set of Java classes for defining the geometry, handling the analysis data associated with the geometry, executing external analysis methods, and pre- and post-processing analysis results. Users of this software will have the ability to use the library of geometry and data classes, through its API, to create wrappers for performing analysis, or for interfacing with external analysis methods. A pre-defined set of wrappers has been created for several software codes used by NASA. These wrappers have also been integrated into several process models for performing analysis and design of conceptual-level aircraft concepts in preparation for additional analysis using higher-order methods. Users of the software will be able to use the API to create wrappers for their own analysis methods, and to use both built-in and custom wrappers to create their own process models for the conceptual-level analysis and design processes used by their organization.

Library of classes representing various coordinate systems and providing the transformations between them. Coordinate systems represented are: East-North-Up (ENU), Downrange-Crossrange-Above (DCA), Latitude-Longitude-Altitude (LLA), Earth-Centered-Fixed (ECF), and Azimuth-Elevation-Range (AER).

The OS Abstraction Layer (OSAL) project is a small software library that isolates embedded software from the underlying operating system. The OSAL does this by providing an Application Program Interface (API) to an abstract real time operating system. The OSAL then provides implementations of this API for two Real Time Operating Systems: vxWorks and RTEMS. In addition, an implementation is provided for Linux/POSIX for embedded Linux projects, and desktop development and testing. To facilitate the use of these APIs, the project also includes a directory structure and set of makefiles that facilitate building a project for a particular OS and hardware platform. Unit tests and several examples are included.

PRECiSA (Program Round-off Certifier via Static Analysis) is a fully automatic static analyzer for floating-point valued functions. It computes an over-approximation of the round-off error of a given floating-point expression, along with a formal certificate that ensures the correctness of the estimated error.

MFS (Multi-Fidelity Simulator) is a pluggable framework for creating an air traffic flow simulator at multiple levels of fidelity. The framework is designed to allow low-fidelity simulations of the entire US Airspace to be completed very quickly (on the order of seconds). The framework allows higher-fidelity plugins to be added to allow higher-fidelity simulations to occur in certain regions of the airspace concurrently with the low-fidelity simulation of the full airspace.

SolFlyte enables the analysis of Solar-Electric (SE) HALE aircraft and airship concepts and missions by uniquely modeling the complex interactions of time-dependent astronomical, geographical, and atmospheric factors on key metrics such as the energy balance, shadowing, performance, on-site persistence, and design size. Separate functional utilities are linked using the PHX ModelCenter v9.0 integration framework to create the SolFlyte-HTA (airplane), SolFlyte-LTA (airship) analysis models, and the SolFlyte-WND wind data processing model. The flexible inputs and rapid execution of the SolFlyte models broadens the analysis scope and permits parametric design feedback.

This software provides a means for simulating supersonic and hypersonic flows efficiently and accurately (under certain restrictions). The parabolized Navier-Stokes (PNS) equations are solved using an upwind finite-volume algorithm that is implicit in the marching direction. The solver includes models for turbulent flow and equilibrium- and finite-rate air chemistry.

The Multiphysics Algorithm with Particles (MAP) is a multidimensional adaptive Cartesian implementation of the direct simulation Monte Carlo (DSMC) method with paralellization capabilities using MPI. The DSMC method is widely used for the modeling of gas flows through the computation of the motion and collisions of representative molecules. Computation at the molecular level is necessary for studies in rarefied gas dynamics (RGD) because the transport terms in the Navier-Stokes equations are not valid in this flow regime. The essential characteristic of a "rarefied" flow is that the molecular mean free path is not negligible. The software has been designed to be as automated as possible to achieve a quality solution with minimal user input and control by performing dynamic adaptations of the grid, local time step, and surface temperature. The gas model includes internal degrees of freedom (rotational, vibrational, and electronic), gas phase chemical reactions, and surface reactions. MAP uses an N-Level embedded Cartesian grid system and a separate surface geometry that is embedded within the grid that is made up of unstructured triangular elements.

The app was created using free app development software from glideapps.com. The information in the app was collected from public domains using google, nasa.gov public sites, wikipedia, and YouTube. It is a repository of information so that students can learn about NASA, it's mission, where the Centers are located, how they can connect NASA internships on social media platforms, and answer frequently asked questions about NASA internships.

HyperSolve AD Mini-App uses an in-house developed AD tool that is based on operator-overloading too compute linearizations of a given function.

FRET is a framework for the elicitation, formalization and understanding of requirements. FRET allows its user to enter hierarchical system requirements in a structured natural language. Requirements written in this language are assigned unambiguous semantics. FRET supports its user in understanding this semantics and reformulating requirements if applicable, by utilizing a variety of forms for each requirement: natural language description, formal mathematical logics, diagrams, and interactive simulation. FRET exports requirements into forms that can be used by a variety of analysis tools, such as Cocosim, Simulink Design Verifier, Kind, and SMV.

ADOPT (abbr. Automatic Discovery Of Precursors in Time series) is a data mining/ machine learning algorithm that processes large volumes of time series data and identifies precursors to adverse events. An adverse event may refer to any unsafe event ranging from a negligible safety hazard to a catastrophic accident, depending on the scope of the analysis. A precursor is an early indicator of an increasing likelihood of the adverse event. Identifying precursors is important in the context of a proactive safety management because precursors detect the increasing severity of the underlying hazard much earlier, giving sufficient time to identify, analyze and implement corrective actions. ADOPT analyzes large volumes of historical data to find complex trends among several sensory variables simultaneously to find precursors. ADOPT's data mining approach captures real-world effects such as human factors, weather, geographic constraints, operating procedures, airline strategies etc. that are difficult to capture using first-principle models. The following are ADOPT's capabilities - new functionality to discover precursors to events of interest by mining time series data, reduces the time required by subject matter experts to discover and analyze precursors from large volumes of data, detects the likelihood of the adverse event earlier to alert the operator on an impending failure, assists in explaining the event of interest with identified precursors. The ADOPT algorithm is a general methodology that does not make any special assumptions about the system and does not need specialized knowledge on the system states enabling it to operate directly on the observed time series data. Further, it can scale well to multivariate time series and can analyze large number of flights, which may enable a faster turnaround time for subsequent tasks such as hazard identification and safety risk analysis. A subject matter expert may require a few hours to analyze a flight for precursors which is not scalable considering the thousands of flights operated on a daily basis. Also, human experts may not be able to visualize hundreds of time series variables to notice complex variations and trends in the data. ADOPT may be used to speed this process by analyzing the thousands of flights that operate every day to short-list only the significant precursors which may then be analyzed by a subject matter expert, reducing the turnaround time for safety analysis. While the motivation to find precursors came from analyzing safety (negative events), the method is general to be applied to performance issues as well as to understand positive events such as finding precursors to a high throughput operation at an airport.

PyTurbo is NASA Turbomachinery design tool capable of going from a 2D Airfoil Design to a 3D design of a blade and a blade row. This design tool can wrap heatpipe paths inside the airfoil. PyTurbo is a turbomachinery design tool focused on the development of 3D blade rows consisting of 3D Airfoils. There is a need inside NASA to develop our own airfoils, this enables fundamental research into transition, tip leakage passive flow control, cavity flows, and nature inspired shapes. PyTurbo serves as a NASA open-sourced fundamental research design code that anyone at NASA can use. PyTurbo is built with the intent that it can be easily incorporated into the python package index (https://pypi.org/).

The engine icing risk prediction code, COMDES-MELT, is a mean-line compressor analysis code coupled with an ice crystal thermodynamic state code. The COMDES-MELT code computes the velocity, pressure, temperature, and flow angles at the leading edge and trailing edge of each blade row, at the hub, mean, and tip sections. This compressor code includes the ability to calculate the effects of water vapor on the fluid properties of the air water vapor mixture based on the mole fraction of air to water vapor. The relative humidity at the engine inlet is specified, and the local specific humidity (mass of water/mass of air) is computed through each component of the inlet-fan-LPC, taking the sublimation, melting, and evaporation of an ice particle into consideration, as well as the local air temperature. The resulting effect of the humid air on the performance of the compressor is computed. Several key parameters have been identified as early indicators of ice accretion: the local wet-bulb temperature, the melt ratio within each blade row, and the ice water flow rate to air flow rate ratio. The local wet-bulb temperature is calculated at each blade row. The geometry section of the code is defined by simple circular arc rotors and stators including stage axial gaps. As the ice particles passes though the compression rotors, stators, and gaps the ice particle melting and evaporation model computes the local melt ratio, change in enthalpy, and particle temperature and diameter through each compressor component. The ratio of ice water flow rate to the air flow rate is computed at the inlet based on the ice water content in the atmosphere and the mass flow rate of air entering the engine. If the limiting values of these key parameters are met, there is a risk that ice will accrete on the surfaces of the compressor. With these parameters as the precursors to ice accretion, the blade row within the compression system can be identified that is likely to experience ice buildup at a particular engine operating condition in the vehicle flight trajectory.

SUMKEM is fully implicit, parabolic, partial-differential equation solver that can be used for the integration of unsteady 3D turbulence kinetic energy and dissipation-rate equations. The technology enables any laminar computational fluid dynamics (CFD) solver to compute a given unsteady turbulent flow of interest.

The Pegasus software is used as a pre-processor for overset-grid Computational Fluid Dynamics (CFD) simulations. It provides the hole-cutting and connectivity information between structured overset grids. The main features of the software include automated hole-cutting algorithms, a projection scheme for fixing small discretization errors in overset surface; efficient interpolation search methods; hole-size optimization based on adding additional layers of fringe points; and an automatic restart capability. The code can run in parallel using the Message-Passing Interface (MPI) standard. The parallel performance provides efficient speed-up of the execution time utilizing dozens or even hundreds of processors. The additional capabilities in the new 5.2 version include: support for cell-centered grids; triple-fringe option; automated domain decomposition into multiple hole-cutters; improved parallel execution load-balancing algorithm; and additional minor enhancements.

DAIDALUS (Detect and AvoID Alerting Logic for Unmanned Systems) is a software library that implements a detect-and-avoid concept for unmanned aircraft systems. At the core of the concept, there is a mathematical definition of the well-clear concept. Two aircraft are considered to be well clear of each other if appropriate distance and time variables determined by the relative aircraft states remain outside a set of predefined threshold values. These distance and time variables are closely related to variables used in the Resolution Advisory (RA) logic of the Traffic Alert and Collision Avoidance System Version II (TCAS II). DAIDALUS includes algorithms for determining the current well-clear status between two aircraft and for predicting a well-clear violation within a lookahead time, assuming non-maneuvering trajectories. DAIDALUS implements algorithms for computing maneuver guidance, assuming a simple kinematic trajectory model for the ownship. Maneuver guidance is computed in the form of range of track, ground speed, vertical speed, and altitude values called bands. These bands represent areas in the airspace the ownship has to avoid in order to maintain well-clear with respect to traffic aircraft. In the case of a loss of well-clear, or when a well-clear violation is unavoidable, the maneuver guidance algorithms provide well-clear recovery bands. Recovery bands represents areas in the airspace that allow the ownship to regain well-clear status in a timely manner according to its performance limits. Recovery bands are designed so that they also protect against a user-specified minimum horizontal and vertical separation. DAIDALUS also implements a pair-wise alerting logic that is based on a list of increasingly conservative alert levels. DAIDALUS is implemented in C++ and Java. The definition of a family of well-clear volumes is also available in Matlab. The software library is modular and highly configurable. The functional requirements of DAIDALUS algorithms have been formally specified in the Prototype Verification System (PVS). The correctness of these algorithms with respect to their functional requirements has been formally verified in PVS. Furthermore, the software implementations have been validated against the formal models using stressing test cases.

The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) has been updated to version 5.6. This is a computational fluid dynamics simulation software code. The new technologies regard techniques for modifying the computational grid, for modeling rough walls, and for interpreting simulations that incorporate a shock layer radiation model.

DAA-Displays (Detect-and-Avoid Display Widgets) is an open-source framework for creating interactive cockpit display simulations. The framework includes widgets for typical Detect and Avoid applications such as maneuver guidance bands, alerting symbols, aircraft states, etc.

Plot3D is a widely used format for storing grid data for numerical computation particularly in CFD. This free open source python library enables researchers to have programmatic access to read, write, combine, plot3D files to build a 3D domain. One of the main challenges with simulations using Plot3D is finding the connection of blocks of I,J,K indexing representing X,Y,Z coordinates in space. This tool contains functionality to automatically finds matching faces of each block and exports the results as a human readable dictionary or JSON format.

A collection of tools and scripts that will create shock-fitted unstructured grids in a mostly automatic manner, similar to those created for structured grids. The scripts has been tested with several unstructured grid solvers, LociCHEM, FUN3D, and US3D, and can be made to work with most other unstructured CFD solvers. The script help to improve numerical stability and convergence when solving hypersonic cases with unstructured CFD solvers. This package also contains an advanced mesh extrusion tool which creates high quality prismatic layers using face offsetting method to preserve surface curvature and a mean curvature smoothing algorithm to prevent the cells from self-intersecting in concave regions.

The Core Flight Executive (cFE) is a software framework designed for use on embedded systems. The cFE defines an Application Programmer Interface (API) to the following services: Software Bus, Time Services, Event Services, Executive Services, Table Services, and File Services. The cFE defines a portable application runtime environment that allows developers to rebuild the same applications code and run it on many different hardware/operating system platforms. The same application code can be developed and unit tested on a desktop environment then ported to the target-embedded processor for final verification and validation.