This book had collected different directions of the mechanics of fluids, gases and multiphase flows. This book are useful as an additional material to main direction namely: creating rockets, creating airplanes, creating ships, creating a multiphase vehicles and another things!!. This book consist of some chapters: liquid, gas, multiphase flow. Also there are a description the each formulas and symbols. Before writing the mathematics models it was learned with comments perhaps to compress liquids or not.Whether there are conditions which do not compress gases or all gases are compressed. Is it really to make the liquid or gas will have a supersonic parameters or not. Each chapter is using only the one-dimensional or two-dimensional mathematics models which it is necessary to explore the each task, graphics and pictures of this flow. This book had been written by author with using multi language text. All pictures had been taken from the internet and it do not show the secret material. The author did not put a problem to duplicate any educational books.