Application of chimera technique to projectiles in relative motion

Abstract : This report describes the application of the versatile Chimera numerical technique to a time-dependent, multibody projectile configuration. A computational study was performed to determine the aerodynamics of small cylindrical segments being ejected into the wake of a flared projectile. The complexity and uniqueness of this problem results from the segments being in relative motion to each other, embedded in a nonuniform wake flow, and requiring a time-dependent solution. Flow field computations for this multibody problem have been performed for supersonic conditions. The predicted flow field over the segments was found to undergo significant changes as the segments separated from the parent projectile. Comparison of the unsteady Chimera results with the quasi-static approach shows the difference in drag history to be significant which indicates the need for time-dependent solution techniques. A subsequent experimental program was conducted in the Army Research Laboratory's (ARL) transonic Range and the computed segment positions and velocities were found to be in good agreement with the experimental data. Aerodynamics, Multiple bodies, Unsteady flow, Chimera, Wake, Drag

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