The Study On Launch Interior Ballistics Of Underwater Guns

The interior ballistic characteristics of underwater gun and conventional gun are significant differences in different work environment. Thus the ballistic characteristics of underwater gun’s firing is studied in detail in this thesis.This thesis briefly introduces the development of this subject’s research and the domestic and foreign research’s situation of the underwater gun. According to the knowledge of fluid mechanics, we know that there are two water column flows in front of the underwater gun muzzle:laminar flow and turbulent flow. This thesis introduces the basic equation, the velocity distribution and the average flow velocity of the water column when The water column flow is laminar flow front in front of projectile. This thesis also introduces the internal structure of the water column when the water column is turbulent flow. So the frictional head loss formula is derived and the value of λis identified in two kinds of flow pattern. Describes the motion process of underwater gun interior ballistic projectile and the existence forms of several of energy. In determining the powder shape function and several assumption, according to the firing laws of the conventional gun interior ballistic, Newton’s second law and Newton’s third law,we established the equations that is suitable for the interior ballistic of underwater gun’s firing. The interior ballistic movement process of the projectile can be divided into four periods, The interior ballistic equations of the four different periods is deduced in detail. At the same time, only changing the depth of water, the underwater gun interior ballistic equations are simulated and the simulation results is analyzed and interpreted. Comparison chart lists of the experimental results and simulation results in depth5m, the simulation results and the test results are in good agreement. In the trend, the simulation curve and test curve are in good agreement. Prove the correctness of equations of the underwater gun interior ballistic, And also proved that the parameters of model we selected are consistent with the actual, the calculation methods are correct. Based on all above, we discussed the effects of the factors in the underwater gun interior ballistic when such as charge quantity, powder force, the weight of the projectile, The length of the gun barrel and the projectile start pressure.Through simulation of underwater gun interior ballistic model, we studied and analyzed the various phenomena in the bore of underwater gun interior ballistic period from the theory and experiment, We relevant the rules and the facts that influence the rules in the process of firing. The simulation results and experimental results indicate that the theoretical model is feasible. The establishment of underwater gun interior ballistic equations provides a theoretical basis for the design and manufacture of underwater weapons.