Numerical Investigation to Study the Effects of Wing Flexibility on the Store Trajectory Using MSC CoSim

Traditional flight testing and wind tunnel testing require expensive resources in terms of time and cost. Safety and cost concerns in the testing of store separation necessitates the need for a numerical analysis. This paper studies the effect of wing flexibility on store separation trajectory by coupling the fluid dynamics of the airflow with the elastic structural behavior of the wing. The co-simulation is performed by using the MSC CoSim engine that couples structural behavior simulated in MSC Nastran and fluid dynamics simulated in Cradle CFD. The simulation Mach number for this analysis is 0.95. The Eglin Test Model of a flexible wing is used for analysis at Mach number 0.95. The objective of the paper is to investigate the flexibility effects of the wing on the store trajectory. The solver has been validated using a rigid wing of the Eglin Test Model for store drop and then extended to perform the store drop simulation from a flexible wing. The study focuses on comparing the linear and angular displacements of the store dropping from the rigid wing and the flexible wing. It was observed that the trajectory of the store for the flexible wing case showed deviation from the trajectory of the store for the rigid wing.