COMPUTATIONAL MODEL OF PROJECTILE IMPACT INTO FUEL TANKS

THE OBJECTIVE OF THIS WORK IS TO INVESTIGATE THE UTILITY OF COMPUTATIONAL FLUID DYNAMIC (CFD) MODELS TO SIMULATE REACTIONS WITHIN FLUID-FILLED TANKS IMPACTED BY WARHEAD FRAGMENTS. IN PHASE I, WE WILL DEVELOP A TWO-DIMENSIONAL (CYLINDRICAL GEOMETRY) MODEL WHICH CONTAINS THE SALIENT PHYSICAL FEATURES NECESSARY TO PARAMETRIZE THE COMPLEX PROCESSES ASSOCIATED WITH FRAGEMENT IMPACT ON FUEL TANKS. WE USE A MODIFIED ARBITRARY LAGRANGIAN EULERIAN (ALE) FLUID MODEL WHICH CONTAINS SPECIAL FEATURES NECESSARY TO CALCULATE THE PENETRATION PROCESS, INCLUDING ELASTIC-PLASTIC PHYSICS AND THE ACCURATE TREATMENT OF MATERIAL BOUNDARIES THOUGH A NOVEL VOF SCHEME. WE SHALL ALSO USE RENORMALIZATION GROUP (RNG) METHODS, DEVELOPED RECENTLY BY US, TO TREAT THE INTERACTION BETWEEN THE SHOCK AND FLUID TURBULENCE IN THE TANK. BY CARRYING OUT SYSTEMATIC NUMERICAL SIMULATIONS, WE WILL DETERMINE THE CHARACTER OF THE HIGHLY TRANSIENT EVENTS OF TANK PENETRATION AND THE ACCOMPANYING MOMENTUM ENERGY TRANSFER TO THE FLUID WITHIN THE TANKS SUBSEQUENT TO PENETRATION. TRANSIENT PRESSURE SIGNATURES AND STRESSES CAN THEN BE EXTRACTED FROM THE COMPUTATIONS AND USED TO TEST FOR TANK RUPTURE.