Numerical modelling of partially filled aircraft fuel tanks submitted to Hydrodynamic Ram

Abstract

a b s t r a c t Keywords:Hydrodynamic Ram Fluid-structure interaction Aircraft vulnerability Impact Fuel tank Hydrodynamic Ram (HRAM) is a phenomenon that occurs when a high-kinetic energy object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure, increasing the risk of catastrophic failure and excessive structural damage. This is of particular concern in the design of wing fuel tanks for aircraft since it has been identified as one of the important factors in aircraft vulnerability. Usually the HRAM phenomenon is analyzed considering completely filled tanks, but its effect on partially filled containers should also be taken into account due to the fact that tanks use to be impacted under these conditions. In the present paper, the commercial finite element code LS-DYNA has been used to simulate an HRAM event created by a steel spherical projectile impacting a partially water-filled aluminium square tube. The ALE formulation is employed to reproduce the event. Experimental tests which indicate the pressure at different points of the fluid, displacement of the walls and cavity evolution for different impact velocities, are compared with the numerical results in order to assess the validity and accuracy of the ALE technique in reproducing such a complex phenomenon.

Numerical Analysis of the Hydrodynamic Ram Phenomenon in Aircraft Fuel Tanks

“…Later on [57,58] fully coupled numerical models were developed to simulate the problem; these models were validated with experimental results, faithfully reproducing them, and the most appropriate techniques to simulate the HRAM phenomenon were pointed out. In the 750 mm long, 150 mm wide and 2.5 mm thick.…”

Numerical analysis of CFRP fluid-filled tubes subjected to high-velocity impact

“…The simulation of coupled problems of fluid-structure interaction such as HRAM added to the modelling of carbon fiber composites, has been proven to be a complicated task and is still quite challenging [51,50]. The suitability and predictive …”

Numerical analysis of high velocity impacts on unidirectional laminates

“…These requirements have propelled in the last decades the use of composite materials, particularly CFRP unidirectional laminates. In this context, the structural problem of high velocity impact of debris on aircraft components of composite materials has become a subject of intense interest [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], not only from the point of view of experimental research [17][18][19] but also from the perspective of numerical simulation and virtual testing, given its potential for reducing the total cost of development of aeronautic structures [20][21][22][23][24][25][26]. These computational aspects are the subject of the present work, which deals with the development of a numerical methodology able to faithfully reproduce the behavior of carbon/epoxy laminates under high velocity impact of small debris.…”