impact on a partially filled tank

Hi I am trying to model a tank filled with air and water which then impacted by a bullet. I am modelling air and water separately and using the eulerian body type. upon interacting with bullet, only water has deformation and air is unaffected (75% water and 25% air) which gives incorrect result. Which interaction properties should i use for water and air or what is correct way to model fluids ( I am new to abaqus).