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A solid fuel launch vehicle is a rocket with an engine that has been widely used in aerospace missions. Utilizing such launch vehicles depends on the simplicity of the manufacturing, maintenance, operation and development of the control systems. The purpose of optimization in solid fuel launch vehicles design is to find the best possible design for the mission with regard to the available equipment, constraints and infrastructures. Therefore, the main purpose of this research is to optimally design a launch vehicle for customized missions based on successful experiences, as well as technology, manufacturing capabilities and facilities. In this context, NSGA-II Intelligent Optimization Algorithm is considered based on multi-objective optimization principles and Mass-Energetic concepts. The optimal design of the launch vehicle is performed by applying intelligent algorithms and technological opportunities and limitations. The result showed that the present optimization method can design the launch vehicle based on technological limitations.

Diaphragm tanks are a common type of pressurized tanks in which the diaphragm is used to separate the fuel part from the high-pressure part, compress the fuel in the tank, and reduce free space to avoid liquid fuel sloshing. The main purpose of the application of the diaphragm tanks is to ensure the continuous flow of pure fuel without the gas bubble into the spacecraft engine. In space mission, diaphragm tanks will experience a wide range of acceleration at different levels of filling. These conditions change the state of equilibrium between the volume of the gas and the fluid and move the diaphragm toward the discharge portion of the tank. As a result of this movement, the diaphragm curvature is changed and the structure collapses at rest, which is called folding. When large nonlinear folding occurs, there is potential for diaphragm damage through wear, rubbing, and excessive stress. Predicting diaphragm behavior in order to calculate a diaphragm’s susceptibility to corrosion, rupture, and surface strain is one of the major design challenges. In this study, new method is provided to analyze deformation of diaphragm tanks by using numerical techniques. Also, the investigation method is verified by using experimental methods. In this process, first a 3D numerical model is developed to investigate the inverse behavior of a hyper-elastic diaphragm by using ANSYS software and the results of the simulations are compared with the results of experimental tests in the same situation. After validation, a second case study is performed to survey the effect of reducing diaphragm thickness according to the strain energy and natural frequency behavior of the diaphragm in different fill levels. The results of this study showed that numerical simulations are capable of reconstructing diaphragm inversion properties with good accuracy. In addition, the numerical model can detect the proper thickness for the diaphragm. In the last section, algorithm and software for optimal automatic modeling of diaphragm tanks are proposed.