Separation dynamics of large-scale fairing section: A fluid-structure interaction study

The separation dynamics of a large-scale fairing section in ground test is investigated numerically using a fluid-structure interaction method. The commercial finite element software MSC/Dytran is adopted to establish the dynamic fluid- structure coupling model of the fairing. Two coupling surfaces are constructed for the inner and outer surfaces of the fairing section. The coupling equations are solved using the sequenced-coupling method, in which the fluid and structural problems are examined by the finite volume method and the finite element method, respectively. A comparison between fluid-structure interaction and dynamical response analysis is performed under the conditions with and without atmosphere effect. Results shown that the consideration of atmosphere effect will attenuate the vibration frequency and slow down the center of mass velocity. The effect of aerodynamic interference on the displacement response indicates that a maximum of 13.3% relative displacement can be induced, which may cause collision between the lower trailing portion of fairing section and the core vehicle. Therefore, it can be concluded that the fluid-structure interaction analysis is essential for evaluating and validating the reliability of separation mechanisms in ground tests.