design algorithm

This research presents a comprehensive data-driven and modeling-based approach to facilitate and improve the design process of waterjet propulsion systems. Initially, a comprehensive statistical design model is developed by extensively reviewing the existing literature and collecting experimental data from commercial examples. Subsequently, two conceptual design algorithms are proposed based on this model to streamline the initial design process. The accuracy and validity of these algorithms are evaluated by comparing their results with available experimental data. Finally, as a case study, a conceptual design of a 500 kW waterjet propulsion system is carried out using these algorithms. The results of this research demonstrate that the proposed method is an efficient and accurate approach for the conceptual design of waterjet propulsion systems. By combining statistical analysis and modeling, this method enables rapid and accurate estimation of design parameters. Additionally, by providing a systematic framework, it assists designers in achieving optimal designs.

Electroaerodynamic (EAD) propulsion has gained considerable attention in aerospace research due to its ability to generate thrust even in rarefied atmospheres at high altitudes. This study presents a comprehensive analysis of the performance and optimization of a decoupled EAD propulsion system, emphasizing its potential advantages over conventional propulsion technologies. A hybrid genetic algorithm–sequential quadratic programming (GA-SQP) approach was employed to optimize the system across various thrust levels. The optimized results were compared with traditional electric motors, offering insights into key trade-offs between the two systems. Findings indicate that while the EAD propulsion system operates at higher voltages than electric motors—resulting in increased power consumption—it provides a distinct advantage in terms of weight. As thrust levels rise, the system's mass exhibits only a marginal increase. For thrust levels between 10 and 70 N, the maximum mass increment is limited to 333 g, making EAD propulsion particularly suitable for applications requiring high thrust-to-weight efficiency. Sensitivity analysis further reveals that increasing system volume enhances thrust without proportionally increasing power consumption, albeit at the cost of additional mass. Additionally, increasing the voltage across the system’s electrodes improves thrust and power consumption without affecting mass. Although higher power consumption necessitates larger energy storage and conversion systems, the minimal mass increase relative to thrust highlights the EAD propulsion system as a promising alternative for high-altitude and space applications where weight constraints are critical

The aim of this study is to evaluate the performance of water-jacket cooling system for thermal protection of an exhaust large dimension diffuser at high heat fluxes in a wide range of coolant pressure. For this purpose, a suitable design algorithm has been developed. Using the present method, the parameters of the water-jacket cooling system are determined so that in addition to satisfying the temperature conditions of the metal body, the total pressure drop has remained in the desired range. In the following, the capability of numerical code to design and performance analysis of the cooling system has been evaluated in coolant pressure of 3 to 50 bar and high heat fluxes up to 3.5 MW/m2. The present studies show that the proper selection of coolant pressure is very important in the design of the cooling system with optimal mass flow rate and minimum coolant dimensions, especially at high heat fluxes, so that increasing the coolant pressure from 3 to 10 bar, in addition to significantly reducing the dimensions of the cooling system, reduces the mass flow rate by 75%.

Usually, ground testing of space engines is performed in high altitude test facility. The facility is equipped with a supersonic diffuser that expels automatically engine gases to the atmospheric pressure and maintains a vacuum pressure around its nozzle and motor. If the motor pressure is lower than a certain amount, the supersonic flow in the diffuser will not be established. In this situation, it is necessary to use auxiliary ejector at the end of the diffuser. In the present study, a new algorithm has been developed in the design of supersonic ejector. Unlike conventional methods, this algorithm can be used for different primary (input from the ejector nozzle) and secondary fluids (outlet from the diffuser end). In the design of the ejector, the main parameters are determined by the algorithm, while the secondary parameters are selected from the empirical test results of the proved references. In this algorithm, a safe margin is considered for the safe operation of the ejector and this margin is predicted by numerical simulation. Also, numerical simulation is used to validate the design method. Finally, using the proposed algorithm, an ejector is designed to reduce the start-up pressure of an engine-diffuser assembly. An integrated simulation of the diffuser-ejector was performed for both cases that rocket motor is off and on, and the appropriateness of the designed ejector was confirmed in both modes of operation