Linearized Aeroelastic Gust Response Analysis of a Launch Vehicle

摘要

Amethodology for aeroelastic gust response of launch vehicles in flight is developed by using a previously validatednaeroelastic stability analysis. The effects on the aeroelastic vibrations of a launch vehicle encountering a wind gustnwhile operating at a particular supersonic flight condition are determined. A linearized dynamic aeroelastic analysisnof the launch vehicles is performed using the previously developed procedure, but this time in supersonic flow. Then,nthe pressure on the moving launcher surface resulting from the combined motion induced by each elastic mode isnobtained from the solution of the Euler equation. These effects are superimposed to determine the combinednaerodynamic effects of all themodes. Thus, a generalized aerodynamic forcematrix of the aerodynamic loads causednby themotion of the launch vehicles (rigid body, aswell as elastic deformations) and the effect of a gust encountered innthe flight is constructed. Finally, a generalized (iterative) eigenvalue analysis is performed to evaluate the aeroelasticnstability of the linearizedmodel of the launch vehicles, operating at the prescribed flowconditions,when it encountersna gust. This approach, along with the use the matched-filter theory on the resulting frequency response function,nallows one to evaluate the effects of the worst-case excitation on the launch vehicle’s aeroelastic response. Thenmethodology has been applied to predict successfully the aeroelastic stability of LYRA launch vehicles when it fliesnthrough transverse gusts.