Attitude model of spinning warhead with cooled shroud when liquid nitrogen is consuming

An attitude dynamics model of spinning warhead flying at free stage with a cooled shroud was established while liquid nitrogen filled in porous medium layer was consuming. The effect of liquid nitrogen movement to spinning warhead is difficult to calculate and simulate directly in engineering, according to this, an infiltration movement model of mixture in porous medium was gained by using homogeneous assumption, then was analyzed by applying dimensionless method, and an applied attitude model was obtained. Simulation shows that angular velocity is increasing in spinning direction, but in other directions, frequencies of angular velocities are increasing while these velocities are not zero, meanwhile, damp effects are appeared in the angular movement. Because of little impaction to attitude angular, both frequencies increase and damp effects could be ignored in practical project.