Researches On The Wear And Erosion Of Bore And Its Influence To Interior Ballistic Performance

Interior ballistic performance, which is an important tactical characteristic of the gun, is affected directly by erosion and wear of the bore, with the more and more application of the gun in the modern war, the researches on erosion-wear and its influence on the interior ballistic performance have become important. In this thesis, a series of experimental and theoretical studies focused on this problem have been presented. The main points are as follows:1. The variations of land diameter of several different kinds of guns are measured and the photographs of the bore surface are taken, the general rules and reasons are known as: erosion and wear are the greatest at the origin of rifling and becomes smaller and meaner in other parts. There is an increasing tendency for erosion and wear at the muzzle in some other guns. The rise of temperature of bore surface caused by the heat effect of propellant gas is the main reason of wear and erosion, however the direct reason of it is the scouring of propellant gas, the chemical effect, and the mechanical wear of band.2. The land diameter wear figure of gun and corresponding parameters of the interior ballistic performance are tested with experimental method. According to their correlativity, some experimental formulas are set up. Using these formulas, the ulterior ballistic performance variation of the gun in different wearing degree can be predicted by measuring the land diameter wear figure.3. By analyzing the engraving procedure, corresponding formula is induced. Interior ballistic performance variation caused by lowers of engraving pressure, chamber volume increasing and projectile trip reduction is calculated through setting up interior ballistic system of equations. The result proved the ulterior ballistic performance is dropping and the variation of curve p-t, v-t, T-t, p-l, v-l, T-l is flatter and flatter in the procedure of erosion and wear.4. The similarity of interior ballistic performance variations of wearing and erosional gun is researched by the similar-analysis based on the zero-dimensional model and two-phase flow model of interior ballistic.5.Through the method of directing shooting and multiple regression analysis forcalculating EFC, the total round number that the gun can shoot during its useful life can be calculated.6. A formula between wear figure and round number is set up. By analyzing the prominence, the correspondence and the precision of this formula, the round number that wearing and erosional gun can shoot and has shot can be calculated.