Jump to content

Recommended Posts

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By Space Force
      The new squadron, which falls under Space Delta 11, marks a critical milestone in advancing the Space Force’s ability to test, train, and prepare for cyber threats in the contested space domain.

      View the full article
    • By NASA
      1 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      NASA’s X-59 quiet supersonic research aircraft completed its first maximum afterburner test at Lockheed Martin’s Skunk Works facility in Palmdale, California. This full-power test, during which the engine generates additional thrust, validates the additional power needed for meeting the testing conditions of the aircraft. The X-59 is the centerpiece of NASA’s Quesst mission, which aims to overcome a major barrier to supersonic flight over land by reducing the noise of sonic booms.Lockheed Martin Corporation/Garry Tice NASA completed the first maximum afterburner engine run test on its X-59 quiet supersonic research aircraft on Dec. 12. The ground test, conducted at Lockheed Martin’s Skunk Works facility in Palmdale, California, marks a significant milestone as the X-59 team progresses toward flight.
      An afterburner is a component of some jet engines that generates additional thrust. Running the engine, an F414-GE-100, with afterburner will allow the X-59 to meet its supersonic speed requirements. The test demonstrated the engine’s ability to operate within temperature limits and with adequate airflow for flight. It also showed the engine’s ability to operate in sync with the aircraft’s other subsystems.
      The X-59 is the centerpiece of NASA’s Quesst mission, which seeks to solve one of the major barriers to supersonic flight over land by making sonic booms quieter. The X-59’s first flight is expected to occur in 2025.
      Share
      Details
      Last Updated Dec 20, 2024 EditorDede DiniusContactMatt Kamletmatthew.r.kamlet@nasa.gov Related Terms
      Aeronautics Aeronautics Research Mission Directorate Armstrong Flight Research Center Commercial Supersonic Technology Integrated Aviation Systems Program Low Boom Flight Demonstrator Quesst (X-59) Supersonic Flight Explore More
      2 min read NASA, Notre Dame Connect Students to Inspire STEM Careers
      Article 4 hours ago 2 min read NASA Flight Rerouting Tool Curbs Delays, Emissions
      Article 4 hours ago 3 min read Atmospheric Probe Shows Promise in Test Flight
      Article 1 week ago Keep Exploring Discover More Topics From NASA
      Armstrong Flight Research Center
      Aeronautics
      Supersonic Flight
      Quesst: The Vehicle
      View the full article
    • By European Space Agency
      Global warming is driving the rapid melting of the Greenland Ice Sheet, contributing to global sea level rise and disrupting weather patterns worldwide. Because of this, precise measurements of its changing shape are of critical importance for adapting to climate change.
      Now, scientists have delivered the first measurements of the Greenland Ice Sheet’s changing shape using data from ESA's CryoSat and NASA's ICESat-2 ice missions.
      View the full article
    • By NASA
      2 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      NASA Deputy Administrator Pam Melroy and Deputy Associate Administrator Casey Swails visit the American Airlines Integrated Operations Center near Dallas Fort Worth International Airport on a recent trip to see NASA’s digital tools for aviation efficiency in operational use.American Airlines It’s the holiday season — which means many are taking to the skies to join their loved ones.
      If you’ve ever used an app to navigate on a road trip, you’ve probably noticed how it finds you the most efficient route to your destination, even before you depart. To that end, NASA has been working to make flight departures out of major international airports more efficient — thereby saving fuel and reducing delays — in close collaboration with the aviation industry and the Federal Aviation Administration (FAA). 
      The savings are possible thanks to a NASA-developed tool called Collaborative Digital Departure Rerouting. 
      This tool determines where potential time savings could be gained by slightly altering a departure route, based on existing data about delays. The software presents its proposed more-efficient route in real time to an airline, who can then decide whether or not to use it and coordinate with air traffic control through a streamlined digital process. 
      The capability is being tested thoroughly at Dallas Fort Worth International Airport and Love Field Airport in Texas in collaboration with several major air carriers, including American Airlines, Delta, JetBlue, Southwest, and United. 
      Now, these capabilities are expanding out of the Dallas area to other major airports in Houston for further research. 
      “We’re enabling the use of digital services to greatly improve aviation efficiency,” said Shivanjli Sharma, manager of NASA’s Air Traffic Management — eXploration project which oversees the research on aviation services. “Streamlining airline operations, reducing emissions, and saving time are all part of making an efficient next-generation airspace system.” 
      NASA / Maria Werries The animation above shows the savings Collaborative Digital Departure Rerouting is responsible for at just a single airport. As the tool is expanded to be used at other airports, the savings begin to add up even more. 
      It’s all part of NASA’s vision for transforming the skies above our communities to be more sustainable, efficient, safer, and quieter. 
      Collaborative Digital Departure Rerouting is one of a series of new cloud-based digital air traffic management tools NASA and industry plan to develop and demonstrate as part of the agency’s Sustainable Flight National Partnership. These new flight management capabilities will contribute to the partnership’s goal of accelerating progress towards aviation achieving net-zero greenhouse gas emissions by 2050. 
      About the Author
      John Gould
      Aeronautics Research Mission DirectorateJohn Gould is a member of NASA Aeronautics' Strategic Communications team at NASA Headquarters in Washington, DC. He is dedicated to public service and NASA’s leading role in scientific exploration. Prior to working for NASA Aeronautics, he was a spaceflight historian and writer, having a lifelong passion for space and aviation.
      Facebook logo @NASA@NASAAero@NASA_es @NASA@NASAAero@NASA_es Instagram logo @NASA@NASAAero@NASA_es Linkedin logo @NASA Explore More
      2 min read NASA, Notre Dame Connect Students to Inspire STEM Careers
      Article 19 mins ago 4 min read NASA Finds ‘Sideways’ Black Hole Using Legacy Data, New Techniques
      Article 2 days ago 8 min read 2024 in Review: Highlights from NASA in Silicon Valley 
      Article 3 days ago Keep Exploring Discover More Topics From NASA
      Missions
      Humans in Space
      Climate Change
      Solar System
      Share
      Details
      Last Updated Dec 20, 2024 Related Terms
      Aeronautics Aeronautics Research Mission Directorate Air Traffic Management – Exploration Air Traffic Solutions Airspace Operations and Safety Program Ames Research Center Green Aviation Tech Sustainable Flight National Partnership View the full article
    • By NASA
      Download PDF: Contact Dynamics Predictions Utilizing theNESC Parameterless Contact Model

      Modeling the capture of the Mars Sample Return (MSR) Orbiting Sample (OS) involves understanding complex dynamic behavior, which includes the OS making contact against the interior of the capture enclosure. The MSR Program required numerical verification of the contact dynamics’ predictions produced using their commercial software tools. This commercial software used “free” parameters to set up the contact modeling. Free parameters (also known as free variables) are not based on contact physics. The commercial contact model used by MSR
      required seven free parameters including a Hertzian contact stiffness, surface penetration, stiffening exponent, penetration velocity, contact damping, maximum penetration depth for the contact damping value, and a smoothing function. An example of a parameter that is not free is coefficient of friction, which is a physics-based parameter. Consider the free parameter, contact stiffness. Contact stiffness is already present in the finite element model’s (FEM) stiffness matrix where the bodies come into contact, and surface penetration is disallowed in a physically realizable contact model, as FEM meshes should not penetrate one another during contact (i.e., the zero-contact limit penetration constraint condition).
      As such, with each set of selected free parameters generating a different contact force signature, additional numerical verification is required to guide setting these parameters. Contact modeling is nonlinear. This means that the stiffness matrices of contacting bodies are continuously updated as the bodies come into contact, potentially recontact (due to vibrations), and disengage. The modal properties of contacting bodies continuously change with state transitions (e.g., stick-to-slip). Some contact models have been proposed and incorporated in commercial finite element analysis solvers, and most involve static loading. A relatively smaller number involve dynamics, which has historically proven challenging.

      In 2005, NASA conducted a study testing several commercial contact solvers in predicting contact forces in transient dynamic environments. This was necessitated by the Space Shuttle Program (SSP)—after the February 2003 Columbia accident— deciding to include contact dynamics in the Space Shuttle transient coupled loads analysis (CLA) to capture the impact of contact nonlinearities. This rendered the entire CLA nonlinear. The study found major difficulties executing nonlinear CLAs in commercial software. A nonlinear solver developed by the NESC and Applied Structural Dynamics (ASD) that was able to produce physically realizable results was numerically verified by NASA and later experimentally validated as well. This nonlinear solver was subsequently utilized to execute all NASA SSP CLAs (i.e., crewed space flights) from 2005 to the final flight in 2011, as well as currently supporting the SLS Program.
      The objective of the MSR contact verification work was to provide data that could be used by the MSR team to help define the free parameters listed above for the commercial tool contact model. The NESC/ASD solver was used to model contact between simple cantilever and free beams, deriving contact forces and relative displacements. These resulting data can be used to determine parameter values for more complex structures. Two of the modeled configurations, one for axial contact (Figure 1) and the other for stick/friction (Figure 2), and sample results from the NESC nonlinear dynamic analyses are presented in Figures 1 and 2.

      For information, contact:
      Dr. Dexter Johnson dexter.johnson@nasa.gov
      Dr. Arya Majed arya.majed@nasa.gov
      View the full article
  • Check out these Videos

×
×
  • Create New...