In [1] the variational principle of the extremum for a viscous incompressible and compressible fluid is proposed, from which it follows that the Navier-Stokes equations are the conditions for the unique extremum of a certain functional. A method is also proposed for the search for this extremum, which is simultaneously a method for solving these equations. Here we based on this method describe the program for calculating the Fluid Flow in Tube with Obstacle - calculating the velocity and pressure of the liquid at all points of the tube.