Applications of second order linear differential equations to model a hydrodynamic ram cavity
Document Type
Conference Proceeding
Publication Date
1-7-2019
Abstract
Hydrodynamic ram events cause numerous aircraft safety issues. Modeling hydrodynamic ram events is important to predict internal cavity phases. In particular, the cavity collapse phase strongly correlates to the main spurt of liquid ejecta from the penetration orifice. This research applies a mathematical model to describe a cavity in a water-filled tank while the cavity undergoes a hydrodynamic ram event. The system’s displacement, damping, and natural frequency are estimated with optical measurements. This model is comparable to a springmass-damper system where the cavity expansion, collapse, and oscillation are treated as a single degree of freedom system. The oscillatory period is correlated to the system’s natural frequency. The cavity’s radial expansion and contraction is analogous to displacement, while measuring the decrement of the displacement peaks allows for the computation of the system’s damping coefficient. Estimation of the equivalent system stiffness and projectile energy dissipation are obtainable from these parameters. Applying this method to hydrodynamic ram events simplifies the overall system and provides a method for predicting the hydrodynamic response. This understanding will allow researchers to better model and understand hydrodynamic ram events, leading to safer aircraft.
Source Publication
AIAA Scitech 2019 Forum
Recommended Citation
Nesmith, A. D., Lingenfelter, A. J., Hess, J. A., & Liu, D. (2019, January 7). Applications of second order linear differential equations to model a hydrodynamic ram cavity. AIAA Scitech 2019 Forum. AIAA Scitech 2019 Forum, San Diego, California. https://doi.org/10.2514/6.2019-0523
Comments
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