Abstract: To calculate a very complicated jet flow in the vertical launcher on a warship, a three dimensional Navier Stokes equation is solved with a standard k ε turbulent model. The method of calculation is of finite volume and the grid used is that of structural mesh. Positions of the missile relative to the launching box include the initial, when reaching the 1/4, 2/4, 3/4 and 4/4 length until the bottom of the launching equipment. Some contours and information are mentioned to study this jet flow dee...