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3D visualization of propellant stress in the space shuttle SRB at .0965 seconds into firing. Stresses range from -4.8 atmospheres in the purple regions to 31.4 atmospheres in the red regions. An atmosphere is a unit of pressure equal to the pressure of air at sea level, or about 14.7 pounds per square inch. The negative value indicates tension (in which the propellant stretches), while positive values indicate compression. The simulation was executed on NCSA's 256-processor SGI Origin2000 and visualized using CSAR's Rocketeer. |
defeat inertia by delivering power. The two solid rocket boosters (SRBs) strapped to the space shuttle provide most of the thrust to lift a 4.5 million pound spacecraft off the ground. In the two minutes that the SRBs burn before they separate from the rest of the craft and fall away, the shuttle achieves a speed of 3,100 miles per hour and an altitude of 25 miles.
But behind this brutish task is incredible complexity in the physics of the craft, in the materials used, and in their interactions. The SRBs are 125 feet long, but a millimeter crack can cause a failure. The amount of sunlight shining on an SRB while it's sitting on the launch pad can affect performance. And a variety of "fiendishly complex" physical processes take place during any solid rocket's firing, according to Michael Heath, director of the Center for Simulation of Advanced Rockets (CSAR).
CSAR is currently meeting all of this complexity head on, using the Alliance's SGI Origin2000 array to create massive, integrated computer models of firing SRBs.
"Our simulations will be useful as a virtual prototyping and design tool, but they will also help us understand rocket failure and improve the safety and reliability of solid rockets of all kinds," says Heath, who is also a computer science professor at the U of I and a senior research scientist at NCSA. "Sometimes simulations will save money, and sometimes they'll save lives."
Access Online | Posted 4-11-2000