Research On The Theory Of Firing Table Design At High Altitude For Artillery Systems

In this dissertation, a systematic research has been made on the theory of firing table design at high altitude above sea level for artillery systems. First, the characteristics and development trend of modern firing table design methods are analyzed and summarized. The disadvantage and improvement of the traditional methods are pointed out. Considered the advanced munitions, the general equations of flight dynamics and control for projectiles and rockets are developed, witch are formulated in mathematical matrix and can be used conveniently to analyze and compute numerically the ballistic and control properties of various projectiles and rockets. In order to find out the factors causing the errors of firing table at high altitude, the influence of the plateau condition on the ballistic properties is systematically analyzed, including the effects of meteorological conditions and aerodynamic parameters on the flight stability, flight attitude, shot dispersion and trajectory elements. It is found out that the main factor causing the errors of firing tables at high altitude is the varity of air drag coefficient with the altitude above sea level, and that the ballistic model of high order should be applied to improve the accuracy of a firing table at high altitude. The partition technique of solving the ballistic model of high order is developed, and hence the difficulty of the small numerical step and the slow computational speed in use of the ballistic model of high order is overcame. The two-variant function model of air drag coefficient of a projectile varying with Mach number and altitude is presented at the first time, in witch the non-uniform B spline technique is applied and so the relation of the drag coefficient and Mach number can be made to loser to the actual situation. Based on the previous researches, the new design technique of a high altitude firing table is presented, witch principle is that the total trajectory of projectile is measured with the modern ballistic measurement means, the ballistic basic data relative to the altitude is attained from the test results, the several characteristic points of the actual trajectory are made to fit completely in with the results produced by the precise ballistic model, and the firing table is computed and arranged by using the modified theoretical ballistic model. The true procedure of the completely fitting computation for the firing table design is provided, in witch the 5 fitting coefficients of the elevation angle, azimuth angle, drag coefficient, lift coefficient and static moment coefficient are computed with the space position measurement of the total trajectory. It expands the theory of firing table design. Because the existence of difficulty of tests for the high altitude firing table, the tests can be implemented at the original firing test base at lower altitude with the new design technique of firing tables. In the paper, the reslts of the firing tests at the lower and higher altitude are used to compare the two design techniques of the traditional and new firing tables at high altitude, and it is showed that the accuracy of the high altitude firing table can be increased greatly by the new technique. The new technique can be widely applied to design the high altitude firing table of various artillery sysytems.