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Here are some of the most important applications being run by NAS staff and our partners on the high-end computers at the NASA Advanced Supercomputing facility.
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NAS SOFTWARE APPLICATIONS
Cart3D
Cart3D is a high-fidelity inviscid analysis package for conceptual and preliminary aerodynamic design. It allows users to perform automated computational fluid dynamics analysis on complex geometry.
Cart3D is currently playing an integral role in NASA's Return to Flight (RTF) effort. Simulations of tumbling debris from foam and other sources, generated using Cart3D, are being used to assess the threat that shedding such debris poses to various elements of the Space Shuttle Launch Vehicle.
Image above: This image shows an unsteady Cart3D simulation used to predict the trajectory of a piece of tumbling foam debris released during ascent. The colors represent surface pressure.
debris
The debris software package includes programs for computing debris trajectories relative to a vehicle in flight, for detecting possible debris impacts on any part of the flight vehicle, and for filtering, sorting, and managing very large databases of debris impacts.
The debris code is being used to compute debris trajectories, which characterize the debris environment experienced by the Space Shuttle Launch Vehicle during ascent. Understanding this debris environment is critical to NASA's Return to-Flight effort.
Image above: This image shows a number of debris trajectories computed by the debris code, which is being used to characterize the debris environment experienced by the Space Shuttle Launch Vehicle during ascent.
Estimating the Circulation and Climate of the Ocean (ECCO)
This application is used to conduct large-scale, high-resolution ocean modeling and analysis in the framework of the ECCO Consortium, which involves NASA's Jet Propulsion Laboratory (JPL), the Massachusetts Institute of Technology (MIT), and the Scripps Institute of Oceanography.
Researchers from the NASA Advanced Supercomputing Division, JPL, and MIT have partnered to dramatically accelerate development of a global eddy-resolving ocean and sea-ice reanalysis. Estimates of time-evolving ocean and sea-ice circulations are obtained by constraining the MIT general circulation model with both satellite and in-situ observations such as sea level, sea-ice extent, and hydrographic profiles. Scientists use these realistic, full-ocean-depth circulation estimates to understand how ocean currents and sea-ice affect climate, to study air-sea exchanges, to improve seasonal and long-term climate predictions, and for many other applications. This is a contribution to the consortium for ECCO.
Image above: Simulated near-surface current speed and sea-ice cover illustrate the tremendous complexity of the global-ocean and sea-ice circulations. Color scale, black to red to white, indicates current speed and ranges from 0 to 50 cm/s. Land masses are overlaid with NASA satellite imagery. White areas at the Poles depict land-ice and sea-ice.
The NASA Finite Volume General Circulation Model (fvGCM)
fvGCM is a global climate and weather prediction model traditionally used for long-term climate simulations at a coarse (approximately100 km) horizontal resolution.
The fvGCM code has been running on Columbia, producing real-time, high-resolution (approximately 25 km) weather forecasts focused on improving hurricane track and intensity forecasts. The code has been remarkably successful during the active 2004 Atlantic hurricane season, providing landfall forecasts with an accuracy of approximately 100 km up to five days in advance. This record marks an improvement in advanced warning beyond the typical two- to three-day lead-time.
Image above: A snapshot of clouds from the fvGCM as hurricane Frances makes landfall on the Gulf coast of Florida and hurricane Ivan intensifies in the tropical Atlantic.
INS3D
This code solves the incompressible Navier-Stokes equations in three-dimensional generalized coordinates for both steady-state and time varying flow.
During long-duration space missions, astronauts must adapt to altered circumstance of microgravity. Blood circulation undergoes significant adaptation during and after space flight. The bloodflow through an anatomical Circle of Willis configuration is simulated using the INS3D code to provide means for studying gravitational effects on the brain's circulation.
Image above: The brain uses the connective arterial tree, called the Circle of Willis, to distribute oxygenated blood throughout the brain mass. To assess the impact of changing gravitational forces on human space flight, it is essential to quantify the blood flow characteristics in the brain under varying gravity conditions.
Overflow
A computational fluid dynamics program for solving complex flow problems. Overflow is widely used by NASA and industry for designing launch and re-entry vehicles, rotorcraft, ships, and commercial aircraft, among others.
The Overflow code is being used to compute the flowfield around the Space Shuttle Launch Vehicle to study the air loads acting on the vehicle due to several design changes, and to study the potential impacts from any debris that might be shed during the ascent.
Image above: This image depicts the flowfield around the Space Shuttle Launch Vehicle traveling at Mach 2.46 and at an altitude of 66,000 feet. The surface of the vehicle is colored by the pressure coefficient, and the gray contours represent the density of the surrounding air.
The Parallel Ocean Program (POP)
POP is the oceanic component of the Community Climate System Model (CCSM), a fully coupled global climate model that enables accurate simulations of the Earth's past, present, and future climate states.
The POP code was ported, and optimized to scale almost linearly to 512 processors of Columbia. This test case will feature a North Atlantic Ocean model at 1/10th degree resolution being simulated at about six years per day.
Image above: Surface velocity of the North Atlantic based on a simulation using the Parallel Ocean Program (POP) Version 1.4.3 with a 0.1 degree resolution.
PHANTOM
PHANTOM is a three-dimensional, unsteady, all-speed flow code developed for turbomachinery applications. The code, written using the Generalized Equation Set, can be applied to both gases and liquids.
Recently, the PHANTOM code has been used to do some analysis in the Flow Liner Crack Investigation. For example, to analyze the surface pressure on the Space Shuttle Main Engine's low-pressure fuel pump inducer, operating in liquid hydrogen.
Image above: Plot of the surface pressure on the Space Shuttle Main Engine's low-pressure fuel pump inducer, operating in liquid hydrogen.
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