| Abstract: | The present article gives a method for the direct measurement of the friction force of cylindrical samples strongly compressed along the axis at the wall of the bore of a gun with a small velocity of the motion, modelling the behavior of a piston in a ballistic unit. As an example, the article gives the results of measurements with a polymer material, i.e., caprolon. On the basis of an experimental investigation, a new friction model is constructed, which is used for the solution of the problem of the internal ballistics of a single stage powder unit with a piston made of caprolon. The laws of similarity of the processes under consideration are investigated. It is established that the value of the maximal pressure of the powder gases and velocity of the piston depend essentially on the value of the friction coefficient.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 76–83, May–June, 1978. |
