Ballistic Simulation And Optimization Based On A Naval Gun

As the thorough study for the system engineering theory, separately numerical simulation of ballistic process cannot satisfy system research and design of gun system, especially on studying a new gun or ammunition system. The main parameters of ballistic performance are analyzed, and this paper mainly focuses on building a whole ballistic simulation platform and optimal design software based on the ship-borne gun system, the main parts are concluded as follows:(1) A simulation platform for whole ballistic process based on the ship-borne gun system is established, and in order to meet the engineering requirements, various simulation models for each ballistic phase are built. Interior ballistic phase contains lumped-parameter model and one-dimensional two-phase flow model; exterior ballistic phase contains point-mass trajectory model and rigid body trajectory model; terminal ballistic phase contains armor piercing model and fragment shot-line model. Aerodynamic engineering algorithm is used to calculate aerodynamic coefficients. The whole trajectory of a ship-borne gun fire guided projectile is simulated by this software. The result indicates that the software can realize the predictability of ballistic process and calculate ballistic performance parameters.(2) The main influence factors on ballistic process are analyzed for optimization. Each ballistic phase of interior ballistic performance, aerodynamic-exterior ballistic performance and terminal ballistic performance is studied with ignition model, charging model, gun structure, geometry of ammunition, warhead and kill element etc. After analysis these factors from the whole perspective, the comprehensive factors which affect the process of the whole trajectory are selected for optimization design variables.(3) Genetic algorithm which is used to optimize ballistic performance has obvious superiority compared with traditional optimization methods. The characteristics of ballistics calculation are analyzed, and from the following aspects the simple genetic algorithm is improved:real-number encoding, adaptive operator, and niche technology, then an improved genetic algorithm is proposed. Through the computational example, its Tightness and effectiveness is validated.(4) Multi-Objective optimization algorithm:Non-dominated Sorting Genetic Algorithm-Ⅱ (NSGA-Ⅱ) is studied thoroughly. A typically application of multi-objective optimization problem is researched to prove the algorithm reasonable. Then the interior ballistic multi-objective optimization model based on one-dimensional two-phase flow model is established, and muzzle velocity, pressure wave and muzzle pressure are set as objectives. In the light of interior ballistic practical problem, the NSGA-Ⅱ with a "filter" is employed to approximate the set of Pareto solutions, and the ranking of Pareto solutions is based on the technique for order preference by similarity to ideal solution (TOPSIS) method. The result indicates that the NSGA-Ⅱ using in ballistic optimization is feasible and reasonable.(5) The necessity of building systemic optimal software is put forward. General method and steps in the design of gun system are studied using modern optimization theory, and then the optimal software is carried out. It has multiple functions, such as single-objective or multi-objective optimal on each ballistic phase and whole ballistic optimal. For the purpose of the optimal software proper and usefulness, a ship-borne gun system equipped with conventional ammunitions and new guided ammunition type are made as examples. Focus on different design purpose, the single-objective and multi-objective optimization models are established, including objectives, design variables and constraint conditions. Compared the obtained optimal schemes, it provides the design direction of the development of new ammunition system.