## Abstract

Simulations were conducted to study the effect of spacecraft vibrations on the directional solidification of a dendritic alloy. Finite element calculations were done with a simulator based on a continuum model of dendritic solidification, using the Fractional Step Method (FSM). An important difficulty common to all solidification models in which the energy equation is expressed in terms of temperature, and that are based on finite elements or finite differences, arises when the interdendritic liquid reaches the eutectic temperature and concentration. When a node reaches eutectic temperature, it is assumed that the solidification of the eutectic liquid continues at constant temperature until all the eutectic is solidified. With this approach, solidification is not achieved continuously across an element; rather, the element is not considered solidified until the eutectic isotherm overtakes the top nodes. To overcome this difficulty, a more accurate method is employed for predicting the rate of change of fraction of liquid as the liquid in an element solidifies. The new method enables us to contrast results of simulations in which the alloy is subjected to no gravity or a steady-state acceleration versus simulations when the alloy is subjected to vibration disturbances; therefore, the effect of vibration disturbances can be assessed more accurately. To assess the impact of these vibration perturbations, transient accelerometer data from a space shuttle mission are used as inputs for the simulation.

Original language | English (US) |
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Pages | 6113-6125 |

Number of pages | 13 |

DOIs | |

State | Published - 2004 |

Event | 42nd AIAA Aerospace Sciences Meeting and Exhibit - Reno, NV, United States Duration: Jan 5 2004 → Jan 8 2004 |

### Other

Other | 42nd AIAA Aerospace Sciences Meeting and Exhibit |
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Country/Territory | United States |

City | Reno, NV |

Period | 1/5/04 → 1/8/04 |

## ASJC Scopus subject areas

- Engineering(all)